[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, 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/).