"In the early days of open source development many devs used
cvs. Then lots of people migrated to the next gen of cvs with SVN
(Subversion) and now the third wave is the move to Git.
The PHP open source project his week joined the growing ranks of
projects big and small that use Git. By moving to Git, I fully
expect that PHP development will accelerate. The gap between recent
PHP releases hasn't been great - PHP 5.4 came out at the beginning
of March over two years after PHP 5.3.