Actually I did make one (a hardly-working, incredibly slow one), but I lost the source code somehow, and am unsure where I left my backup.
In any case, I think I may decide to redo the whole highlighter, using a custom engine (I was using GeSHi before, which was why it was so bad), but that'll most likely happen some time after the holidays.
The forum software says we have 554 members online now. We did not have that many unique visitors the whole day today. Too many bots and the disconnect between the forum counts and the stats.