diff --git a/plugins/python-build/bin/pyenv-install b/plugins/python-build/bin/pyenv-install
index 26799b84..cf0413d6 100755
--- a/plugins/python-build/bin/pyenv-install
+++ b/plugins/python-build/bin/pyenv-install
@@ -1,4 +1,21 @@
 #!/usr/bin/env bash
+#
+# Summary: Install a Python version using the python-build plugin
+#
+# Usage: pyenv install [-f|--force] [-k|--keep] [-v|--verbose] <version>
+#        pyenv install [-f|--force] [-k|--keep] [-v|--verbose] <definition-file>
+#        pyenv install -l|--list
+#
+#   -l/--list        List all available versions
+#   -f/--force       Install even if the version appears to be installed already
+#   -k/--keep        Keep source tree in $PYENV_BUILD_ROOT after installation
+#                    (defaults to $PYENV_ROOT/sources)
+#   -v/--verbose     Verbose mode: print compilation status to stdout
+#
+# For detailed information on installing Python versions with
+# python-build, including a list of environment variables for adjusting
+# compilation, see: https://github.com/yyuu/pyenv#readme
+#
 set -e
 [ -n "$PYENV_DEBUG" ] && set -x
 
@@ -15,20 +32,12 @@ fi
 eval "$(python-build --lib)"
 
 usage() {
-  { echo "usage: pyenv install [-k|--keep] [-v|--verbose] VERSION"
-    echo "       pyenv install [-k|--keep] [-v|--verbose] /path/to/definition"
-    echo "       pyenv install -l|--list"
-    echo
-    echo "  -l/--list        List all available versions"
-    echo "  -k/--keep        Keep source tree in \$PYENV_BUILD_ROOT after installation"
-    echo "                   (defaults to ${PYENV_ROOT}/sources)"
-    echo "  -v/--verbose     Verbose mode: print compilation status to stdout"
-    echo
-  } >&2
-
+  # We can remove the sed fallback once pyenv 0.4.0 is widely available.
+  pyenv-help install 2>/dev/null || sed -ne '/^#/!q;s/.//;s/.//;1,4d;p' < "$0"
   [ -z "$1" ] || exit "$1"
 }
 
+unset FORCE
 unset KEEP
 unset VERBOSE
 
@@ -43,6 +52,9 @@ for option in "${OPTIONS[@]}"; do
     python-build --definitions | sed 's/^/  /'
     exit
     ;;
+  "f" | "force" )
+    FORCE=true
+    ;;
   "k" | "keep" )
     [ -n "${PYENV_BUILD_ROOT}" ] || PYENV_BUILD_ROOT="${PYENV_ROOT}/sources"
     ;;
@@ -58,21 +70,82 @@ for option in "${OPTIONS[@]}"; do
   esac
 done
 
+unset VERSION_NAME
+
+# The first argument contains the definition to install. If the
+# argument is missing, try to install whatever local app-specific
+# version is specified by pyenv. Show usage instructions if a local
+# version is not specified.
 DEFINITION="${ARGUMENTS[0]}"
+[ -n "$DEFINITION" ] || DEFINITION="$(pyenv local 2>/dev/null || true)"
 [ -n "$DEFINITION" ] || usage 1
 
+
+
+# Define `before_install` and `after_install` functions that allow
+# plugin hooks to register a string of code for execution before or
+# after the installation process.
+declare -a before_hooks after_hooks
+
+before_install() {
+  local hook="$1"
+  before_hooks["${#before_hooks[@]}"]="$hook"
+}
+
+after_install() {
+  local hook="$1"
+  after_hooks["${#after_hooks[@]}"]="$hook"
+}
+
+# Load plugin hooks.
 for script in $(pyenv-hooks install); do
   source "$script"
 done
 
-VERSION_NAME="${DEFINITION##*/}"
+
+# Set VERSION_NAME from $DEFINITION, if it is not already set. Then
+# compute the installation prefix.
+[ -n "$VERSION_NAME" ] || VERSION_NAME="${DEFINITION##*/}"
 PREFIX="${PYENV_ROOT}/versions/${VERSION_NAME}"
 
-# If PYENV_BUILD_ROOT is set, then always pass keep options to python-build
+# If the installation prefix exists, prompt for confirmation unless
+# the --force option was specified.
+if [ -z "$FORCE" ] && [ -d "${PREFIX}/bin" ]; then
+  echo "pyenv: $PREFIX already exists" >&2
+  read -p "continue with installation? (y/N) "
+
+  case "$REPLY" in
+  y* | Y* ) ;;
+  * ) exit 1 ;;
+  esac
+fi
+
+# If PYENV_BUILD_ROOT is set, always pass keep options to python-build
 if [ -n "${PYENV_BUILD_ROOT}" ]; then
   export PYTHON_BUILD_BUILD_PATH="${PYENV_BUILD_ROOT}/${VERSION_NAME}"
   KEEP="-k"
 fi
 
-python-build $KEEP $VERBOSE "$DEFINITION" "$PREFIX"
-pyenv rehash
+# Set PYTHON_BUILD_CACHE_PATH to $PYENV_ROOT/cache, if the directory
+# exists and the variable is not already set.
+if [ -z "${PYTHON_BUILD_CACHE_PATH}" ] && [ -d "${PYENV_ROOT}/cache" ]; then
+  export PYTHON_BUILD_CACHE_PATH="${PYENV_ROOT}/cache"
+fi
+
+
+# Execute `before_install` hooks.
+for hook in "${before_hooks[@]}"; do eval "$hook"; done
+
+
+# Invoke `python-build` and record the exit status in $STATUS. Run
+# `pyenv rehash` after a successful installation.
+STATUS=0
+python-build $KEEP $VERBOSE "$DEFINITION" "$PREFIX" || STATUS="$?"
+
+# Execute `after_install` hooks.
+for hook in "${after_hooks[@]}"; do eval "$hook"; done
+
+# Run `pyenv-rehash` after a successful installation.
+[ "$STATUS" != "0" ] || pyenv rehash
+
+exit "$STATUS"
diff --git a/plugins/python-build/bin/pyenv-uninstall b/plugins/python-build/bin/pyenv-uninstall
index c152a304..fdf4061c 100755
--- a/plugins/python-build/bin/pyenv-uninstall
+++ b/plugins/python-build/bin/pyenv-uninstall
@@ -1,4 +1,15 @@
 #!/usr/bin/env bash
+#
+# Summary: Uninstall a specific Python version
+#
+# Usage: pyenv uninstall [-f|--force] <version>
+#
+#    -f  Attempt to remove the specified version without prompting
+#        for confirmation. If the version does not exist, do not
+#        display an error message.
+#
+# See `pyenv versions` for a complete list of installed versions.
+#
 set -e
 
 # Provide pyenv completions
@@ -11,7 +22,7 @@ if [ -z "$PYENV_ROOT" ]; then
 fi
 
 unset FORCE
-if [ "$1" = "-f" ]; then
+if [ "$1" = "-f" ] || [ "$1" = "--force" ]; then
   FORCE=true
   shift
 fi
@@ -19,15 +30,9 @@ fi
 DEFINITION="$1"
 case "$DEFINITION" in
 "" | -* )
-  { echo "usage: pyenv uninstall [-f] VERSION"
-    echo
-    echo "   -f  Attempt to remove the specified version without prompting"
-    echo "       for confirmation. If the version does not exist, do not"
-    echo "       display an error message."
-    echo
-    echo "Installed versions:"
-    pyenv versions --bare | sed 's/^/  /'
-    echo
+  # We can remove the sed fallback once pyenv 0.4.0 is widely available.
+  { pyenv-help uninstall 2>/dev/null ||
+    sed -ne '/^#/!q;s/.\{1,2\}//;1,4d;p' < "$0"
   } >&2
   exit 1
   ;;
diff --git a/plugins/python-build/bin/python-build b/plugins/python-build/bin/python-build
index 93e09cfe..35af6df2 100755
--- a/plugins/python-build/bin/python-build
+++ b/plugins/python-build/bin/python-build
@@ -112,7 +112,9 @@ install_package_using() {
   make_package "$package_name" $*
   popd >&4
 
-  echo "Installed ${package_name} to ${PREFIX_PATH}" >&2
+  { echo "Installed ${package_name} to ${PREFIX_PATH}"
+    echo
+  } >&2
 }
 
 make_package() {
@@ -127,27 +129,139 @@ make_package() {
   popd >&4
 }
 
-fetch_url() {
+compute_md5() {
+  if type md5 >/dev/null; then
+    md5 -q
+  elif type openssl &>/dev/null; then
+    local output="$(openssl md5)"
+    echo "${output##* }"
+  elif type md5sum &>/dev/null; then
+    local output="$(md5sum -b)"
+    echo "${output% *}"
+  else
+    return 1
+  fi
+}
+
+verify_checksum() {
+  # If there's no MD5 support, return success
+  [ -n "$HAS_MD5_SUPPORT" ] || return 0
+
+  # If the specified filename doesn't exist, return success
+  local filename="$1"
+  [ -e "$filename" ] || return 0
+
+  # If there's no expected checksum, return success
+  local expected_checksum="$2"
+  [ -n "$expected_checksum" ] || return 0
+
+  # If the computed checksum is empty, return failure
+  local computed_checksum="$(compute_md5 < "$filename")"
+  [ -n "$computed_checksum" ] || return 1
+
+  if [ "$expected_checksum" != "$computed_checksum" ]; then
+    { echo
+      echo "checksum mismatch: ${filename} (file is corrupt)"
+      echo "expected $expected_checksum, got $computed_checksum"
+      echo
+    } >&4
+    return 1
+  fi
+}
+
+http() {
+  local method="$1"
+  local url="$2"
+  [ -n "$url" ] || return 1
+
   if type curl &>/dev/null; then
-    curl -L "$@"
+    "http_${method}_curl" "$url"
   elif type wget &>/dev/null; then
-    wget -O- "$@"
+    "http_${method}_wget" "$url"
   else
     echo "error: please install \`curl\` or \`wget\` and try again" >&2
     exit 1
   fi
 }
 
+http_head_curl() {
+  curl -sILf "$1" >&4 2>&1
+}
+
+http_get_curl() {
+  curl -sSLf "$1"
+}
+
+http_head_wget() {
+  wget -q --spider "$1" >&4 2>&1
+}
+
+http_get_wget() {
+  wget -nv -O- "$1"
+}
+
 fetch_tarball() {
   local package_name="$1"
   local package_url="$2"
+  local mirror_url
+  local checksum
 
-  echo "Downloading ${package_url}..." >&2
-  { fetch_url "$package_url" > "${package_name}.tar"
-    tar xvf "${package_name}.tar"
+  if [ "$package_url" != "${package_url/\#}" ]; then
+    checksum="${package_url#*#}"
+    package_url="${package_url%%#*}"
+
+    if [ -n "$PYTHON_BUILD_MIRROR_URL" ]; then
+      mirror_url="${PYTHON_BUILD_MIRROR_URL}/$checksum"
+    fi
+  fi
+
+  local package_filename="${package_name}.tar" # later tar can read compression algorithm from file
+  symlink_tarball_from_cache "$package_filename" "$checksum" || {
+    echo "Downloading ${package_filename}..." >&2
+    { http head "$mirror_url" &&
+      download_tarball "$mirror_url" "$package_filename" "$checksum"
+    } ||
+    download_tarball "$package_url" "$package_filename" "$checksum"
+  }
+
+  { tar xvf "$package_filename"
+    rm -f "$package_filename"
   } >&4 2>&1
 }
 
+symlink_tarball_from_cache() {
+  [ -n "$PYTHON_BUILD_CACHE_PATH" ] || return 1
+
+  local package_filename="$1"
+  local cached_package_filename="${PYTHON_BUILD_CACHE_PATH}/$package_filename"
+  local checksum="$2"
+
+  [ -e "$cached_package_filename" ] || return 1
+  verify_checksum "$cached_package_filename" "$checksum" >&4 2>&1 || return 1
+  ln -s "$cached_package_filename" "$package_filename" >&4 2>&1 || return 1
+}
+
+download_tarball() {
+  local package_url="$1"
+  [ -n "$package_url" ] || return 1
+
+  local package_filename="$2"
+  local checksum="$3"
+
+  echo "-> $package_url" >&2
+
+  { http get "$package_url" > "$package_filename"
+    verify_checksum "$package_filename" "$checksum"
+  } >&4 2>&1 || return 1
+
+  if [ -n "$PYTHON_BUILD_CACHE_PATH" ]; then
+    local cached_package_filename="${PYTHON_BUILD_CACHE_PATH}/$package_filename"
+    { mv "$package_filename" "$cached_package_filename"
+      ln -s "$cached_package_filename" "$package_filename"
+    } >&4 2>&1 || return 1
+  fi
+}
+
 fetch_git() {
   local package_name="$1"
   local git_url="$2"
@@ -163,6 +277,21 @@ fetch_git() {
   fi
 }
 
+fetch_svn() {
+  local package_name="$1"
+  local svn_url="$2"
+  local svn_rev="$3"
+
+  echo "Checking out ${svn_url}..." >&2
+
+  if type svn &>/dev/null; then
+    svn co -r "$svn_rev" "$svn_url" "${package_name}" >&4 2>&1
+  else
+    echo "error: please install \`svn\` and try again" >&2
+    exit 1
+  fi
+}
+
 fetch_jar() {
   local package_name="$1"
   local package_url="$2"
@@ -186,7 +315,7 @@ build_package() {
   echo "Installing ${package_name}..." >&2
 
   for command in $commands; do
-    "build_package_${command}" "${package_name}"
+    "build_package_${command}"
   done
 
   if [ ! -f "$PYTHON_BIN" ]; then
@@ -252,10 +381,6 @@ build_package_copy() {
   cp -R . "$PREFIX_PATH"
 }
 
-bild_package_noop() {
-  echo "Nothing to do."
-}
-
 before_install_package() {
   local stub=1
 }
@@ -266,7 +391,7 @@ after_install_package() {
 
 fix_directory_permissions() {
   # Ensure installed directories are not world-writable to avoid Bundler warnings
-  find "$PREFIX_PATH" -type d -exec chmod go-w {} \;
+  find "$PREFIX_PATH" -type d \( -perm -020 -o -perm -002 \) -exec chmod go-w {} \;
 }
 
 require_gcc() {
@@ -480,6 +605,33 @@ else
   TMP="${TMPDIR%/}"
 fi
 
+if [ -z "$MAKE" ]; then
+  MAKE="make"
+fi
+
+if [ -n "$PYTHON_BUILD_CACHE_PATH" ] && [ -d "$PYTHON_BUILD_CACHE_PATH" ]; then
+  PYTHON_BUILD_CACHE_PATH="${PYTHON_BUILD_CACHE_PATH%/}"
+else
+  unset PYTHON_BUILD_CACHE_PATH
+fi
+
+if [ -z "$PYTHON_BUILD_MIRROR_URL" ]; then
+  PYTHON_BUILD_MIRROR_URL="" # FIXME: setup mirror site
+else
+  PYTHON_BUILD_MIRROR_URL="${PYTHON_BUILD_MIRROR_URL%/}"
+fi
+
+if [ -n "$PYTHON_BUILD_SKIP_MIRROR" ]; then
+  unset PYTHON_BUILD_MIRROR_URL
+fi
+
+if echo test | compute_md5 >/dev/null; then
+  HAS_MD5_SUPPORT=1
+else
+  unset HAS_MD5_SUPPORT
+  unset PYTHON_BUILD_MIRROR_URL
+fi
+
 SEED="$(date "+%Y%m%d%H%M%S").$$"
 LOG_PATH="${TMP}/python-build.${SEED}.log"
 PYTHON_BIN="${PREFIX_PATH}/bin/python"
@@ -500,8 +652,8 @@ fi
 export LDFLAGS="-L'${PREFIX_PATH}/lib' ${LDFLAGS}"
 export CPPFLAGS="-I'${PREFIX_PATH}/include' ${CPPFLAGS}"
 
-unset PYTHONOPT
-unset PYTHONLIB
+unset PYTHONHOME
+unset PYTHONPATH
 
 trap build_failed ERR
 mkdir -p "$BUILD_PATH"
diff --git a/plugins/python-build/share/python-build/2.5 b/plugins/python-build/share/python-build/2.5
index 9e080cc4..3ada3970 100644
--- a/plugins/python-build/share/python-build/2.5
+++ b/plugins/python-build/share/python-build/2.5
@@ -8,6 +8,6 @@ linux*)
   ;;
 esac
 
-install_package "Python-2.5" "http://www.python.org/ftp/python/2.5/Python-2.5.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.5" "http://www.python.org/ftp/python/2.5/Python-2.5.tgz#bc1b74f90a472a6c0a85481aaeb43f95"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.5.1 b/plugins/python-build/share/python-build/2.5.1
index 24846b86..ae1cbaf3 100644
--- a/plugins/python-build/share/python-build/2.5.1
+++ b/plugins/python-build/share/python-build/2.5.1
@@ -8,6 +8,6 @@ linux*)
   ;;
 esac
 
-install_package "Python-2.5.1" "http://www.python.org/ftp/python/2.5.1/Python-2.5.1.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.5.1" "http://www.python.org/ftp/python/2.5.1/Python-2.5.1.tgz#cca695828df8adc3e69b637af07522e1"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.5.2 b/plugins/python-build/share/python-build/2.5.2
index 6030f4c7..4cf0b07f 100644
--- a/plugins/python-build/share/python-build/2.5.2
+++ b/plugins/python-build/share/python-build/2.5.2
@@ -8,6 +8,6 @@ linux*)
   ;;
 esac
 
-install_package "Python-2.5.2" "http://www.python.org/ftp/python/2.5.2/Python-2.5.2.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.5.2" "http://www.python.org/ftp/python/2.5.2/Python-2.5.2.tgz#3f7ca8aa86c6bd275426d63b46e07992"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.5.3 b/plugins/python-build/share/python-build/2.5.3
index 465c001a..73f432ac 100644
--- a/plugins/python-build/share/python-build/2.5.3
+++ b/plugins/python-build/share/python-build/2.5.3
@@ -8,6 +8,6 @@ linux*)
   ;;
 esac
 
-install_package "Python-2.5.3" "http://www.python.org/ftp/python/2.5.3/Python-2.5.3.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.5.3" "http://www.python.org/ftp/python/2.5.3/Python-2.5.3.tgz#a971f8928d6beb31ae0de56f7034d6a2"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.5.4 b/plugins/python-build/share/python-build/2.5.4
index f347d41f..760a85da 100644
--- a/plugins/python-build/share/python-build/2.5.4
+++ b/plugins/python-build/share/python-build/2.5.4
@@ -8,6 +8,6 @@ linux*)
   ;;
 esac
 
-install_package "Python-2.5.4" "http://www.python.org/ftp/python/2.5.4/Python-2.5.4.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.5.4" "http://www.python.org/ftp/python/2.5.4/Python-2.5.4.tgz#ad47b23778f64edadaaa8b5534986eed"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.5.5 b/plugins/python-build/share/python-build/2.5.5
index 6f46d381..1d427a41 100644
--- a/plugins/python-build/share/python-build/2.5.5
+++ b/plugins/python-build/share/python-build/2.5.5
@@ -8,6 +8,6 @@ linux*)
   ;;
 esac
 
-install_package "Python-2.5.5" "http://www.python.org/ftp/python/2.5.5/Python-2.5.5.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.5.5" "http://www.python.org/ftp/python/2.5.5/Python-2.5.5.tgz#abc02139ca38f4258e8e372f7da05c88"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.5.6 b/plugins/python-build/share/python-build/2.5.6
index 59eafc2c..0f96a33d 100644
--- a/plugins/python-build/share/python-build/2.5.6
+++ b/plugins/python-build/share/python-build/2.5.6
@@ -8,6 +8,6 @@ linux*)
   ;;
 esac
 
-install_package "Python-2.5.6" "http://www.python.org/ftp/python/2.5.6/Python-2.5.6.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.5.6" "http://www.python.org/ftp/python/2.5.6/Python-2.5.6.tgz#d1d9c83928561addf11d00b22a18ca50"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.6.6 b/plugins/python-build/share/python-build/2.6.6
index 1d2d1c0e..20ecf971 100644
--- a/plugins/python-build/share/python-build/2.6.6
+++ b/plugins/python-build/share/python-build/2.6.6
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-2.6.6" "http://www.python.org/ftp/python/2.6.6/Python-2.6.6.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.6.6" "http://www.python.org/ftp/python/2.6.6/Python-2.6.6.tgz#b2f209df270a33315e62c1ffac1937f0"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.6.7 b/plugins/python-build/share/python-build/2.6.7
index ea7631e0..271d9d08 100644
--- a/plugins/python-build/share/python-build/2.6.7
+++ b/plugins/python-build/share/python-build/2.6.7
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-2.6.7" "http://www.python.org/ftp/python/2.6.7/Python-2.6.7.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.6.7" "http://www.python.org/ftp/python/2.6.7/Python-2.6.7.tgz#af474f85a3af69ea50438a2a48039d7d"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.6.8 b/plugins/python-build/share/python-build/2.6.8
index 30569354..d811f1bb 100644
--- a/plugins/python-build/share/python-build/2.6.8
+++ b/plugins/python-build/share/python-build/2.6.8
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-2.6.8" "http://www.python.org/ftp/python/2.6.8/Python-2.6.8.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.6.8" "http://www.python.org/ftp/python/2.6.8/Python-2.6.8.tgz#f6c1781f5d73ab7dfa5181f43ea065f6"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.7 b/plugins/python-build/share/python-build/2.7
index 0d0be1cc..391aaa64 100644
--- a/plugins/python-build/share/python-build/2.7
+++ b/plugins/python-build/share/python-build/2.7
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-2.7" "http://www.python.org/ftp/python/2.7/Python-2.7.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.7" "http://www.python.org/ftp/python/2.7/Python-2.7.tgz#35f56b092ecf39a6bd59d64f142aae0f"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.7.1 b/plugins/python-build/share/python-build/2.7.1
index 869172b3..ad0a21e0 100644
--- a/plugins/python-build/share/python-build/2.7.1
+++ b/plugins/python-build/share/python-build/2.7.1
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-2.7.1" "http://www.python.org/ftp/python/2.7.1/Python-2.7.1.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.7.1" "http://www.python.org/ftp/python/2.7.1/Python-2.7.1.tgz#15ed56733655e3fab785e49a7278d2fb"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.7.2 b/plugins/python-build/share/python-build/2.7.2
index 9039ecb8..7d40c62c 100644
--- a/plugins/python-build/share/python-build/2.7.2
+++ b/plugins/python-build/share/python-build/2.7.2
@@ -1,3 +1,3 @@
-install_package "Python-2.7.2" "http://www.python.org/ftp/python/2.7.2/Python-2.7.2.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.7.2" "http://www.python.org/ftp/python/2.7.2/Python-2.7.2.tgz#0ddfe265f1b3d0a8c2459f5bf66894c7"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/2.7.3 b/plugins/python-build/share/python-build/2.7.3
index 4b6a309d..1a84dc06 100644
--- a/plugins/python-build/share/python-build/2.7.3
+++ b/plugins/python-build/share/python-build/2.7.3
@@ -1,3 +1,3 @@
-install_package "Python-2.7.3" "http://www.python.org/ftp/python/2.7.3/Python-2.7.3.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-2.7.3" "http://www.python.org/ftp/python/2.7.3/Python-2.7.3.tgz#2cf641732ac23b18d139be077bd906cd"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.0.1 b/plugins/python-build/share/python-build/3.0.1
index 5fac796f..c93b6794 100644
--- a/plugins/python-build/share/python-build/3.0.1
+++ b/plugins/python-build/share/python-build/3.0.1
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-3.0.1" "http://www.python.org/ftp/python/3.0.1/Python-3.0.1.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.0.1" "http://www.python.org/ftp/python/3.0.1/Python-3.0.1.tgz#220b73f0a1a20c4b1cdf9f9db4cd52fe"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.1.3 b/plugins/python-build/share/python-build/3.1.3
index f15b743c..a4030771 100644
--- a/plugins/python-build/share/python-build/3.1.3
+++ b/plugins/python-build/share/python-build/3.1.3
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-3.1.3" "http://www.python.org/ftp/python/3.1.3/Python-3.1.3.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.1.3" "http://www.python.org/ftp/python/3.1.3/Python-3.1.3.tgz#d797fa6abe82c21227e328f05a535424"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.1.4 b/plugins/python-build/share/python-build/3.1.4
index 5e164a4f..c2b38284 100644
--- a/plugins/python-build/share/python-build/3.1.4
+++ b/plugins/python-build/share/python-build/3.1.4
@@ -1,3 +1,3 @@
-install_package "Python-3.1.4" "http://www.python.org/ftp/python/3.1.4/Python-3.1.4.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.1.4" "http://www.python.org/ftp/python/3.1.4/Python-3.1.4.tgz#fa9f8efdc63944c8393870282e8b5c35"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.1.5 b/plugins/python-build/share/python-build/3.1.5
index 25782401..92c0e3cd 100644
--- a/plugins/python-build/share/python-build/3.1.5
+++ b/plugins/python-build/share/python-build/3.1.5
@@ -1,3 +1,3 @@
-install_package "Python-3.1.5" "http://www.python.org/ftp/python/3.1.5/Python-3.1.5.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.1.5" "http://www.python.org/ftp/python/3.1.5/Python-3.1.5.tgz#02196d3fc7bc76bdda68aa36b0dd16ab"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.2 b/plugins/python-build/share/python-build/3.2
index 9ea7fa13..fe579f43 100644
--- a/plugins/python-build/share/python-build/3.2
+++ b/plugins/python-build/share/python-build/3.2
@@ -8,6 +8,6 @@ before_install_package() {
   esac
 }
 
-install_package "Python-3.2" "http://www.python.org/ftp/python/3.2/Python-3.2.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.2" "http://www.python.org/ftp/python/3.2/Python-3.2.tgz#5efe838a7878b170f6728d7e5d7517af"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.2.1 b/plugins/python-build/share/python-build/3.2.1
index 04560f25..62ac1a80 100644
--- a/plugins/python-build/share/python-build/3.2.1
+++ b/plugins/python-build/share/python-build/3.2.1
@@ -1,3 +1,3 @@
-install_package "Python-3.2.1" "http://www.python.org/ftp/python/3.2.1/Python-3.2.1.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.2.1" "http://www.python.org/ftp/python/3.2.1/Python-3.2.1.tgz#6c2aa3481cadb7bdf74e625fffc352b2"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.2.2 b/plugins/python-build/share/python-build/3.2.2
index bb005268..0654ab21 100644
--- a/plugins/python-build/share/python-build/3.2.2
+++ b/plugins/python-build/share/python-build/3.2.2
@@ -1,3 +1,3 @@
-install_package "Python-3.2.2" "http://www.python.org/ftp/python/3.2.2/Python-3.2.2.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.2.2" "http://www.python.org/ftp/python/3.2.2/Python-3.2.2.tgz#3c63a6d97333f4da35976b6a0755eb67"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.2.3 b/plugins/python-build/share/python-build/3.2.3
index 251ec2c4..112b7534 100644
--- a/plugins/python-build/share/python-build/3.2.3
+++ b/plugins/python-build/share/python-build/3.2.3
@@ -1,3 +1,3 @@
-install_package "Python-3.2.3" "http://www.python.org/ftp/python/3.2.3/Python-3.2.3.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.2.3" "http://www.python.org/ftp/python/3.2.3/Python-3.2.3.tgz#dcf3a738e7028f1deb41b180bf0e2cbc"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/3.3.0 b/plugins/python-build/share/python-build/3.3.0
index 0c08da43..6700245f 100644
--- a/plugins/python-build/share/python-build/3.3.0
+++ b/plugins/python-build/share/python-build/3.3.0
@@ -1,3 +1,3 @@
-install_package "Python-3.3.0" "http://python.org/ftp/python/3.3.0/Python-3.3.0.tgz"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "Python-3.3.0" "http://python.org/ftp/python/3.3.0/Python-3.3.0.tgz#198a64f7a04d1d5e95ce2782d5fd8254"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/jython-2.5.0 b/plugins/python-build/share/python-build/jython-2.5.0
index 04c055aa..2fa9f0e3 100644
--- a/plugins/python-build/share/python-build/jython-2.5.0
+++ b/plugins/python-build/share/python-build/jython-2.5.0
@@ -1,4 +1,4 @@
 require_java
-install_jar "Jython-2.5.0" "https://downloads.sourceforge.net/project/jython/jython/2.5.0/jython_installer-2.5.0.jar" jython
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_jar "Jython-2.5.0" "https://downloads.sourceforge.net/project/jython/jython/2.5.0/jython_installer-2.5.0.jar#f98b83fce9669feec69d0a17ee515a20" jython
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/jython-2.5.1 b/plugins/python-build/share/python-build/jython-2.5.1
index 65b48b71..c8930b23 100644
--- a/plugins/python-build/share/python-build/jython-2.5.1
+++ b/plugins/python-build/share/python-build/jython-2.5.1
@@ -1,4 +1,4 @@
 require_java
-install_jar "Jython-2.5.1" "https://downloads.sourceforge.net/project/jython/jython/2.5.1/jython_installer-2.5.1.jar" jython
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_jar "Jython-2.5.1" "https://downloads.sourceforge.net/project/jython/jython/2.5.1/jython_installer-2.5.1.jar#2ee978eff4306b23753b3fe9d7af5b37" jython
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/jython-2.5.2 b/plugins/python-build/share/python-build/jython-2.5.2
index 403cb67a..10ce4132 100644
--- a/plugins/python-build/share/python-build/jython-2.5.2
+++ b/plugins/python-build/share/python-build/jython-2.5.2
@@ -1,4 +1,4 @@
 require_java
-install_jar "Jython-2.5.2" "https://downloads.sourceforge.net/project/jython/jython/2.5.2/jython_installer-2.5.2.jar" jython
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_jar "Jython-2.5.2" "https://downloads.sourceforge.net/project/jython/jython/2.5.2/jython_installer-2.5.2.jar#7c7d9abd8985df480edeacd27ed9dcd5" jython
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/jython-2.5.3 b/plugins/python-build/share/python-build/jython-2.5.3
index e20274ae..1113778d 100644
--- a/plugins/python-build/share/python-build/jython-2.5.3
+++ b/plugins/python-build/share/python-build/jython-2.5.3
@@ -1,4 +1,4 @@
 require_java
-install_jar "Jython-2.5.3" "http://search.maven.org/remotecontent?filepath=org/python/jython-installer/2.5.3/jython-installer-2.5.3.jar" jython
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_jar "Jython-2.5.3" "http://search.maven.org/remotecontent?filepath=org/python/jython-installer/2.5.3/jython-installer-2.5.3.jar#41633b4557483d6d4237ee79ffcebe7b" jython
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/pypy-1.8 b/plugins/python-build/share/python-build/pypy-1.8
index bf902081..8d4a5d09 100644
--- a/plugins/python-build/share/python-build/pypy-1.8
+++ b/plugins/python-build/share/python-build/pypy-1.8
@@ -1,24 +1,24 @@
 case "$OSTYPE" in
 darwin*)
-  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-osx64.tar.bz2"
+  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-osx64.tar.bz2#1c293253e8e4df411c3dd59dff82a663"
   ;;
 linux*)
   case $(uname -m) in
   i386|i486|i586|i686)
-    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-linux.tar.bz2"
+    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-linux.tar.bz2#c4a1d11e0283a390d9e9b801a4633b9f"
     ;;
   x86_64)
-    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-linux64.tar.bz2"
+    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-linux64.tar.bz2#3b81363ccbc042dfdda2fabbf419e788"
     ;;
   esac
   ;;
 cygwin*|mingw*)
-  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-win32.zip"
+  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-win32.zip#1af8ee722721e9f5fd06b61af530ecb3"
   ;;
 esac
 
 if [ -n "$PYPY_URL" ]; then
   install_package "pypy-1.8" "$PYPY_URL" pypy
-  install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-  install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+  install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+  install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
 fi
diff --git a/plugins/python-build/share/python-build/pypy-1.9 b/plugins/python-build/share/python-build/pypy-1.9
index 5ade1407..27064586 100644
--- a/plugins/python-build/share/python-build/pypy-1.9
+++ b/plugins/python-build/share/python-build/pypy-1.9
@@ -1,24 +1,24 @@
 case "$OSTYPE" in
 darwin*)
-  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-osx64.tar.bz2"
+  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-osx64.tar.bz2#aad9c4b7b827583e37fe8ae0f7cfe0ff"
   ;;
 linux*)
   case $(uname -m) in
   i386|i486|i586|i686)
-    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-linux.tar.bz2"
+    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-linux.tar.bz2#1a08c88642434fc2e0e4256d351f48db"
     ;;
   x86_64)
-    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-linux64.tar.bz2"
+    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-linux64.tar.bz2#201d2cce2557e40c784473b471ee1b6b"
     ;;
   esac
   ;;
 cygwin*|mingw*)
-  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-win32.zip"
+  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-win32.zip#e7655066baed3c7bbbca7df617817dd5"
   ;;
 esac
 
 if [ -n "$PYPY_URL" ]; then
   install_package "pypy-1.9" "$PYPY_URL" pypy
-  install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-  install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+  install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+  install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
 fi
diff --git a/plugins/python-build/share/python-build/pypy-2.0-beta1 b/plugins/python-build/share/python-build/pypy-2.0-beta1
index db0ef7b5..2780e287 100644
--- a/plugins/python-build/share/python-build/pypy-2.0-beta1
+++ b/plugins/python-build/share/python-build/pypy-2.0-beta1
@@ -1,23 +1,23 @@
 case "$OSTYPE" in
 darwin*)
-  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-osx64.tar.bz2"
+  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-osx64.tar.bz2#2802a06cd19ac86930b63afdd837c32f"
   ;;
 linux*)
   case $(uname -m) in
   armel)
-    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux-armel.tar.bz2"
+    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux-armel.tar.bz2#a1505520c063c591b218e5cd3436b111"
     ;;
   i386|i486|i586|i686)
-    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux.tar.bz2"
+    PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux.tar.bz2#5aa2e4eee1c3dab86e5cec237776ced3"
     ;;
   x86_64)
     LDD_VERSION=$(ldd --version | head -1)
     case "${LDD_VERSION#ldd \(*\) }" in
     2.15)
-      PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux64-libc2.15.tar.bz2"
+      PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux64-libc2.15.tar.bz2#0fde559a7b1a3b98245d6a5ea7f8ebb2"
       ;;
     2.13)
-      PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux64-libc2.13.tar.bz2"
+      PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-linux64-libc2.13.tar.bz2#68d8668299cd5adf4f302eaf882c5b33"
       ;;
     *)
       echo "pypy-2.0-beta1 requires libc version 2.13 or 2.15." 1>&2
@@ -28,12 +28,12 @@ linux*)
   esac
   ;;
 cygwin*|mingw*)
-  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-win32.zip"
+  PYPY_URL="https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-beta1-win32.zip#e46e1c20da6a2d15e34a6ef9afca311f"
   ;;
 esac
 
 if [ -n "$PYPY_URL" ]; then
   install_package "pypy-2.0-beta1" "$PYPY_URL" pypy
-  install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-  install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+  install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+  install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
 fi
diff --git a/plugins/python-build/share/python-build/stackless-2.7.2 b/plugins/python-build/share/python-build/stackless-2.7.2
index 409a6d79..f707a7c7 100644
--- a/plugins/python-build/share/python-build/stackless-2.7.2
+++ b/plugins/python-build/share/python-build/stackless-2.7.2
@@ -1,3 +1,3 @@
-install_package "stackless-272-export" "http://www.stackless.com/binaries/stackless-272-export.tar.bz2"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "stackless-272-export" "http://www.stackless.com/binaries/stackless-272-export.tar.bz2#79a718db998f2cdd95478d2cb54d56f2"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python
diff --git a/plugins/python-build/share/python-build/stackless-3.2.2 b/plugins/python-build/share/python-build/stackless-3.2.2
index 3d73131f..d67599ca 100644
--- a/plugins/python-build/share/python-build/stackless-3.2.2
+++ b/plugins/python-build/share/python-build/stackless-3.2.2
@@ -1,3 +1,3 @@
-install_package "stackless-322-export" "http://www.stackless.com/binaries/stackless-322-export.tar.bz2"
-install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz" python
-install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz" python
+install_package "stackless-322-export" "http://www.stackless.com/binaries/stackless-322-export.tar.bz2#3a3edcfb4240bdcc580cec2baea60af4"
+install_package "distribute-0.6.34" "http://pypi.python.org/packages/source/d/distribute/distribute-0.6.34.tar.gz#4576ab843a6db5100fb22a72deadf56d" python
+install_package "pip-1.2.1" "http://pypi.python.org/packages/source/p/pip/pip-1.2.1.tar.gz#db8a6d8a4564d3dc7f337ebed67b1a85" python