The GNOME foundation announced availability of final release candidate for GNOME 3.18. This release candidate will mark end of another development cycle for world's most widely used open source desktop environment. It is expected that, GNOME 3.18 final will be released within one week.
From a news article published in softpedia
The GNOME development team has revealed that the final RC for GNOME 3.18 has been released and is now available for testing. The stable version of GNOME will arrive in less than a week. The GNOME 3.18 development cycle is pretty much over and developers only have a few days to figure out whether any of the last minute stuff will be accepted into the software. The desktop environment has been following a pretty strict schedule and they managed to keep to it, so it won't be late for the final version.