I bought a licence for UBB and although it was ok it was wather clunky and I couldn't get my cobranding system to work on it with out major hacking which turned out to be completely unscaleable, so I thought, hmm, ok this works but it's not going to turn out the way I hoped, mostly because UBB 5 used static pages

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Then vB 1 came along (just 3 weeks later) and it's pages were all dynamically generated out of database so everything can be modified on the fly, perfect! A few code changes to make the co-branding work and I was off

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The best part of vB is the go to first unread post button, UBB5 sucked because it didn't have that!