Great idea Mark, and as longtime user of basecamp, it’s a wonderful product. Unfortunately, it doesn’t offer some critical things we need on the software side, and the bugtracker + forums + SVN repository is working well. (We used basecamp originally when it was just Raymond and me, and there are some things I miss, but this is working better now, I think.)
Ryan Thrash, MODX Co-Founder
Follow me on Twitter at @rthrash or catch my occasional unofficial thoughts at thrash.me