RC - It is a version code name for the time been until there is an official release with a pkg distribution.
Follow a request, I will have a reason to make a pkg if any one need/want a pkg (a .deb in such case).
If you did have had a chance to try the 0.9.8.13-rc version, It will be great to know the outputs(good/bad) about the version.
So far, the 0.9.8.13-rc version is the current version with apache-hadoop-2.7.6 running in production https://Thither.Direct .
If any one want to join the project Thither.Direct, please let me know, you can email me at kashir...@gmail.com or post here.