This is the latest version of JJ2+. For the first time, JJ2+ is now being distributed as an installer .exe instead of a bunch of random files that you need to figure out for yourself. The installer will also do some handy stuff for you like registering context menu (=right click) actions for your .j2l files in Windows Explorer. There's also some network code changes, some fixes to bugs that made certain servers unjoinable, a less obnoxious spectator mode overlay, and a bunch of other stuff. Check it out, stay updated!
As ever, for full changelog and installation instructions, please consult the readme located in your download or online.