The Wikipedia page mentions that it was running on Scoop, but doesn't include that Scoop was written by Rusty as the framework for k5. Scoop went on to be used

The Wikipedia page mentions that it was running on Scoop, but doesn't include that Scoop was written by Rusty as the framework for k5. Scoop went on to be used in a few other places, among them HuSi (where a bunch of core k5 folks moved to, though it's now pretty defunct as well). The most well-known site I'm aware of that used Scoop was DailyKos, which I believe started on WordPress, then moved to Scoop (highly customized and eventually almost entirely rewritten I think), then finally onto its own custom-build CMS. There may have also been one more stage in there. Source: 3-digit UID on DK, and was a regular way way back when on both k5 and HuSi.