Diff of module version releases
You can clone down the project via

git clone --branch 7.x-2.x http://git.drupal.org/project/custom_formatters.git

When in the directory do a git diff 7.x-2.4..7.x-2.3 and review the output.

If you don't want to scroll through your terminal, try git diff 7.x-2.4..7.x-2.3 &gt; version-change.diff and pop the output into a diff viewer.

I wish cgit had this built it, but the diff viewer in it only supports per commit (as far as I know)