As in the topic. It would be nice to see syntax highliting mod capable to do everything. I'm running programming oriented forum and users are crying for that.
I know that you don't want to mess with GeSHi because of its GPL. But maybe you can do a mod to integrate geshi saying user in readme that he must personally download it and put in some folder? It wouldn't be redistribution of GPL code, modification of it or anything to mess with GPL licence, which I also personally hate.
Also you can use SyntaxHighliter jScript app, which is on LGPL http://alexgorbatchev.com/wiki/SyntaxHighlighter
There is a mod using that for 1.0 http://www.simplemachines.org/community/index.php?topic=337285.msg2264684#msg2264684
and a beta for 2.0 beta4 http://www.simplemachines.org/community/index.php?topic=290024.0
which don't work with 2.0RC2
Maybe somebody can update it or make a new one.
I'm still not sure legally how that stands in licensing terms.
I would also point out the performance impact would not be small on highlighting code.
But as I pointed out (may have been to you), the license issue is not about redistribution, never has been. It's down to the licensing terms in the GPL about linking to non-free software, and under the terms of the GPL, SMF's license is non free (we're even listed on their page as non free)