GeSHi

GeSHi is an excellent syntax highlighter, both in terms of the number of languages it supports, as well as the various different output formats.

I was happy that GeSHi could output valid XHTML using divs and spans, so I could write my own CSS stylesheet to style the code.

The only small problem is that large code blocks can take up significant server CPU. Apparently a future version (1.2) will have some performance and caching features. Until then you can easily implement your own caching mechanism - I'm using memcache for example.

Overall, an excellent project.

I've recently started to help out with GeSHi and concentrated on pushing the performance higher and higher. What does that mean?

version | average speed (5 runs)
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1.0.7.20 | 5.72 kB/s
r1400 soon 1.0.8 | 49.27 kB/s
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So the new GeSHi is nearly ten times as fast! And don't forget 1.0.8 also has bugfixes, more features etc. etc.

Oh and btw.: Peak memory consumption is down one megabyte as well!

I can only say: GeSHi is _the_ highlighter for the web. Even more so with support for more than 100 languages and decent performance.