Basically a fancy word for Beta
. Release Candidates, or "RCs" are usually completed or near-completed software programs, still needing that finishing touch. The program (or it's source code
) is released to a large number of people for further testing. These people report back bugs
, glitches and other anomalies in the software.
After code has reached Release Candidate or Beta status (something which is up to the developer to decide), it is unlikely that the final version will contain any major new features. At this point the main aspects of the software have been finalized, and the bug-hunt starts. It IS possible that some extra functionality is added once in RC/Beta, though.
There is also a big difference between Open and Closed Source Release Candidates. Microsoft, for example, releases a couple thousand RC CD's of Windows whenever a new version comes out. These are distributed in different ways, through computer magazines (competitions, lotteries) for example. It is not possible to use these CDs for an extended period of time, as they virtually "self-destruct" (i.e. a built-in clock renders the software useless after a certain date) after a couple months or so .
Open source RCs, like Ogg Vorbis for instance, are completely open to the public, and freely downloadable. They have no time limit or reduced functionality as is with closed source software. Ogg Vorbis is currently at RC3, which of course means it is the third release candidate. It's main features are set, and what remains to be done is largely bug-fixing and optimizing.