Everyone is welcomed to participate in the mysqlnd development and the extension has seen changes from outside, as well the mysql extensions and we never complained that someone does it. I just moved the changes to our internal revision control system, as Bazaar gives us more freedom to work than CVS - recently there was a Blog entry on planetphp from a dev, who synced PHP but forgot to sync Zend. Wanted to dev while on train but the sources did not build so his time was wasted.
Do you talk about our GIT mirrors? They should build now (git.experimentalworks.net). There were some problems with importing the phar files as they were copied/linked in the CVSROOT, causing problems with branch points.