I've made some tarballs of the httpd-2.1 tree. I just pulled HEAD of both httpd and apr (as of about an hour ago, just before greg's pollset changes). They're here:
http://www.apache.org/~aaron/httpd-2.1.0-rc1/ This seems to work fine on my Mac OS X (10.3 Panther) box, my linux 2.4 x86 box, and my linux x86_64 (amd64 opteron) box. Let me know if there are any problems (and fixes) so I can encorporate the fixes and reroll in a few days. My goal is to churn out updated -rc tarballs every few days until we get one that we like, at which point we'll call it 2.1.0 GA. -aaron