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.
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.
I'm on a page about incorrect corrections, and spent the better part of like two hours trying to get someone to understand that -5^2 = -25, not 25, and then that post had comments get reposted because that group is self sustaining, and that person was in turn trying to explain what I just explained to them. And I'm taking that as a victory