Release Candidate
From GMpedia.org Wiki
A release candidate (RC) is the stage of development where the software has been finalized and is in the form it should be released in.
A release candidate is usually released for public testing to see if there are any serious bugs or problems in the program. If there are any, they are fixed an another release candidate is released. This process continues until no serious bugs remain. When there are no bugs, the software is released to the public.

