在Symfony和Doctrine网站上编码荧光笔

I really like highlighting and tabs that are used for code snippets on symfony.com and doctrine-project.org sites.

I wish I knew how they managed to achive this. Probably they use some special JavaScript library?

From Symfony 2 online documentation:

The Symfony2 documentation uses reStructuredText as its markup language and Sphinx for building the output

So go through these tools' documentation to get an idea on how you can adapt them to your site