Hi,
the sources of siremis are in sourceforge.net svn. If any of you has developed (plan to develop) extensions, contact me to grant devel access. Also, patches should be sent against latest svn trunk (no branches so far):
http://sourceforge.net/projects/siremis/
The svn repo does not store the openbiz core framework -- you have to get it from siremis-1.0.0.tgz (the openbiz dir) or download it from openbiz project and apply the patch from misc directory (note that you also have to download zend and others according to openbiz guides).
Once you fetch siremis svn and add openbiz, run make to create the symlinks required for web dirs and you are set.
Regards, Ramona