http://svn.zope.org is the main Zope source code repository. Anyone can check out a copy of the latest development code from here:
svn co svn://svn.zope.org/repos/main/Zope/trunk Zope
To commit code, you must sign Zope Corporation's committer's agreement and put your code under the ZopePublicLicense?. See http://dev.zope.org/Subversion for more instructions.
2008/04 update:
As most of you probably know, the machine that is known by many names, including mail.zope.org, svn.zope.org, cvs.zope.org, and download.zope.org, died Tuesday morning. Thanks to the heroic efforts of ZC operations staff, all of the services of the old machine were restored onto a new faster machine with a modern operating system. This was done by the end of Tuesday.
One service that didn't make it was the old key-upload application. It used PHP libraries that we didn't want to move to the new box. Also, this program was pretty lame because it used a text area rather than a file upload to input keys. This led to lots of key mangling. I've replaced this application with a micro-Zope application. (This would have been a Bobo application if Bobo still lived. Bobo shall rise again!) The new application is available at:
https://cvs.zope.org/upload-key.html currently uses an invalid security certificateIf you need to change your keys, that's what you should use.
For people who might want to become contributors, I've tried to create comprehensive yet concise set of instructions:
http://www.zope.org/DevHome/Subversion/ImpatientPeoplesGuideToRequestingCommitPrivileges