Linux 4.1 [https://lkml.org/lkml/2015/6/22/8 has been released] on Sun, 21 Jun 2015
Warning This page will be completed in the next few days. Meanwhile, you can read about Linux 4.1 in:
LWN merge window [http://lwn.net/Articles/640297/ part 1], [http://lwn.net/Articles/641016/ part 2], [http://lwn.net/Articles/642039/ part 3]