There is always a current major release and usually a current minor release. They usually represent a major change and have a significant new feature added. It takes a significant amount of testing and thought for a change to make it from development to release. There are few cases where a later interim release was worse than an earlier release. Here is a list of bugs fixed in interim releases.
Interim releases are available for download.
For the most part it puts the intelligence on the server. It also is designed for low-bandwidth connections and connections which might not be up all the time. As far as we know the server has only been implemented once. It includes the basic functionality but no bells and whistles. Affected programs include the CVS client, the VC package for emacs, jCVS, and a vast number of special-purpose scripts.