I was also happy to find it some time ago and also opted for using it (it’s really hard PITA to get back once you got used to haml/slime) in a non-trivial project. Alas, it seems to become abandonware just like all other (?) After kludging around for last two versions of Phoenix, I feel like the need to waste time again and again is no longer worth it. Unless somebody knows a current, maintained fork or another maintained option I’ll end up rewriting lots of slime templates back into [h]eex 
Any other suggestions?
UPDATE: found a fork working with phx 1.7
