CURRENT is where active, cutting-edge development is done. STABLE is much more “settled” than CURRENT. The 5.3 release will likely be in Feb/March 2005, with a5.5 release possibly in June/July, depending on where 6.0 is. Scott Long recommended that further discussion of the 5.x branch move from freebsd-current to freebsD-stable. The current plan is to branch RELENG_6 (aka 6-STABLE) sometime aroundMay or June 2005.”]
Source: https://taosecurity.blogspot.com/2004/11/freebsd-5_05.html