[Goldmark](https://github.com/yuin/goldmark/) is from Hugo 0.60 the default library used for Markdown. It's fast, it's [CommonMark](https://spec.commonmark.org/0.29/) compliant and it's very flexible.
: By default, Goldmark does not render raw HTMLs and potentially dangerous links. If you have lots of inline HTML and/or JavaScript, you may need to turn this on.
typographer
: This extension substitutes punctuations with typographic entities like [smartypants](https://daringfireball.net/projects/smartypants/).
: Enable custom attribute support for titles and blocks by adding attribute lists inside single curly brackets (`{.myclass class="class1 class2" }`) and placing it _after the Markdown element it decorates_, on the same line for titles and on a new line directly below for blocks.
Note that attributes in [code fences](/content-management/syntax-highlighting/#highlighting-in-code-fences) must come after the opening tag, with any other highlighting processing instruction, e.g.:
: The strategy used for creating auto IDs (anchor names). Available types are `github`, `github-ascii` and `blackfriday`. `github` produces GitHub-compatible IDs, `github-ascii` will drop any non-Ascii characters after accent normalization, and `blackfriday` will make the IDs compatible with [Blackfriday](#blackfriday), the default Markdown engine before Hugo 0.60. Note that if Goldmark is your default Markdown engine, this is also the strategy used in the [anchorize](/functions/anchorize/) template func.
This is the default `highlight` configuration. Note that some of these settings can be set per code block, see [Syntax Highlighting](/content-management/syntax-highlighting/).