Created by zeromus and rheiny (aka SP) and joined by mz, adelikat, nitsujrehtona, Ugly Joe, maximus, CaH4e3 (Demul, FCEU-MM), Sebastian Porst (FCEUXD SP), qfox and Lucas Sabota. Without forgetting the work of former authors: Bero (FCE), Xodnizel (FCEU), Bbitmaster & Parasyte (FCEU XD), Blip & nitsuja (FCEU TAS), Luke Gustafson (FCEU TAS+).
The 2.6.6 release is mainly a maintenance update for the mappers and emulation core with a few new features added in.
Some of these new features apply only to the Qt/SDL version of the GUI.