These repositories contain SRPMs, RPMs and source tar files for the software built from https://github.com/opensource-sw.
Each repository is divided into a number of subrepositories, one for binaries (RPMs) and one for source (SRPMs) for each CentOS release.
You can browse the packages available here using repoview:
All RPMS are signed with this key
The pkg-cacher application releases are hosted on SourceForge.
The source, wiki, and issues for all applications are hosted on github.