highlight.js is a library for highlighting code in a beautiful manner.
Highlight is a rather old library, but its 7th version was released just recently with several important updates:
- Size reduced to less than 2k;
- New languages;
- Highlight.js is now node-compatible;
- Numerous bugfixes;
Basically, if you need a comprehensive code highlighting library, pick highlight.js — it’s easy to use, well documented and is of a polyglot nature; for language-specific projects alternatives, such as Rainbow, are also a viable choice.