A release candidate (RC) means that the SMF team feels the product is nearly ready for production. We should be down to the last cycles of testing before an official release.
It is also important to note that between release candidates, SMF does not release update packages.
As a result of the above, those who adopt usage of a release candidate should:
- Expect to find bugs (and help us out by reporting bugs here: https://github.com/SimpleMachines/SMF2.1/issues)
- Be aware that as updates come out, you may need to apply the updates by hand
If you are not comfortable with the above, please wait until the product is formally released!