diff --git a/main.scm b/main.scm
index 865166e..d831c92 100755
--- a/main.scm
+++ b/main.scm
@@ -94,15 +94,29 @@
    (substring* 0 40)))
 
 (define (enumerate-tag tag inner)
-  `(,tag (@ (id ,tag "-" ,(slugify tag inner))) ,inner))
+  `(,tag (@ (id ,(slugify tag inner))) ,inner))
 
-(define sxml-html-rules
+(define (sxml-html-rules adjust-relative)
   `(;; assign all headings an id so you can link to them
     (h1        . ,enumerate-tag)
     (h2        . ,enumerate-tag)
     (h3        . ,enumerate-tag)
     (h4        . ,enumerate-tag)
     (h5        . ,enumerate-tag)
+    ;; if adjust-relative is true, all relative links should get prefixed with
+    ;; the relative-root.
+    ,(if adjust-relative
+         `(a .
+           ,(lambda (t i)
+              `(,t .
+                ,(alist-update
+                  '@
+                  (alist-update
+                   'href
+                   `(,adjust-relative ,(alist-ref 'href (alist-ref '@ i)))
+                   (alist-ref '@ i))
+                  i))))
+         `(a . ,(lambda (t i) `(,t . ,i))))
     ;; this copied from lowdown html-serialization-rules* because it
     ;; is for some reason not exported??
     (*COMMENT* . ,(lambda (_ str) (list #\< "!--" str "--" #\>)))
@@ -219,16 +233,19 @@
             (create-directory destination-directory #t)
             '())
 
-    (let* (;; render the sxml to a html string that we can hand to the template
+    (let* (;; vars = global vars + file-specific vars
+           (vars (alist-merge vars (or newvars '())))
+           (rel-root-prefix (alist-ref 'relative_root vars))
+           ;; render the sxml to a html string that we can hand to the template
            (body-html
             (with-output-to-string
               (lambda ()
-                (SXML->HTML (pre-post-order* body-sxml sxml-html-rules)))))
-           ;; vars = global vars + file-specific vars + body k/v pair
-           (vars
-            (alist-cons
-             'content body-html
-             (alist-merge vars (or newvars '())))))
+                (SXML->HTML (pre-post-order* body-sxml (sxml-html-rules
+                                                        (if (equal? rel-root-prefix "html/")
+                                                            rel-root-prefix
+                                                            #f)))))))
+           ;; vars = vars + body k/v pair
+           (vars (alist-cons 'content body-html vars)))
 
       (with-output-to-file output-filename
         (lambda ()
@@ -237,6 +254,7 @@
 ;; main program ------------------------------------------------------------------------------
 
 (define (generate-html-files html-repo-path templates-directory)
+  ;; git automatically updates this hash when you checkout/pull/etc.
   (let* ((version-ident       "$Id$")
          (source-files-list   (git-repository->paths-list))
          (template-alist