A brief rundown of the repositories:
Multimedia – includes Nvidia driver, CUDA
A repository for HandBrake, the really powerful open source multi threaded video encoder along with awesome MakeMKV ripper (it can rip encrypted Blue Ray and DVDs) and the libdvdcss library.
There are also CUDA enabled builds of Blender and FFMPeg, additional restricted FFMpeg encoders/decoders and multimedia libraries as well as Gstreamer plugins for the various Gnome releases.
A repository that packs the latest Steam for Fedora. This are the same packages that are now integrated in RPMFusion.
A repository that packs the latest Adobe Flash Plugin for Fedora / CentOS / RHEL that tries to be more “compliant”; also used by the Steam repository. Much like what Redhat does for the Flash plugin in RHEL’s supplementary channel.
A repository for cdrtools is available for those that don’t think that cdrkit works enough well. The packages obsoletes the cdrkit packages and plugs into as a replacement for brasero etc. On RHEL 6+ and Fedora the packages uses file capabilities to avoid having the binaries setuid root.
A repository that packs Skype for Fedora and CentOS/RHEL.
Nvidia driver, CUDA tools and libraries
A repository that packs the latest Nvidia driver and all its ecosystem of tools: NVENC, CUDA, etc.. For Fedora and CentOS/RHEL; quite different from the other repositories I found around.
Samsung Unified Linux Driver – Printers & Scanners
A repository that contains the Linux driver for Samsung’s line of scanners, printers and multifunction devices. It supports local and network connected devices.
Wiimms ISO Tools
Wiimms ISO Tools is a set of command line tools to manipulate Wii and GameCube ISO images and WBFS containers. For Fedora and CentOS/RHEL.
Repackaged Ubuntu binaries for Fedora.
RAR archiver, packaged for Fedora and CentOS/RHEL.