Hey there vord. You guessed it, it's custom written. While Morgan conned me into releasing my mod_rewrite tutorial

I would rather keep everything else I have on DaniWeb exclusive to DaniWeb. Tech forums nowadays are a dime a dozen, and it's our unique portal, blogs, code snippets, tutorials, irc chat, and link directory, in addition to all the other mini-hacks I coded (such as our "solved" threads), that make us unique
While our mod_rewrite tutorial was mostly just editing various bits and pieces of vB code and templates (i.e. replacing PHP urls with .html urls) all of the other hacks we've got are thousands of lines of pure PHP code - and damn it I suffered through five years of a computer science undergraduate degree to be able to write code that efficient, optimized, and object oriented!
I will say, however, that there are a couple hacks on vBulletin.org that do a good job of providing the same functionality as we do here at DaniWeb (dare I say, albeit not as cleanly coded).
vB Advanced CMPS is a good alternative to my portal (our moderator Zachery put a lot into this one, I believe). v3 Articles is a good article / tutorial database. If I'm not mistaken there's another vBArticles hack as well. vBJournal is a good blogs script, written by one of DaniWeb's own members, as well. And then there is the Links and Files Database you can also find on vbulletin.org for vB 3. There is also vBxIRC that is based on the same Java chat software as DaniWeb's IRC chat, also created by Zachery.