For the progressives in the house!
Keystone Progress has gathered most of the endorsements by progressive groups and put them into one handy-dandy voter guide. You can view it here.
I noticed that a couple of groups didn't seem to make it into the guide, so here are the endorsements by Planned Parenthood PA PAC and by Progress Pittsburgh PAC.
UPDATE: James in the comments section reminds me that The Pittsburgh 14th Ward Independent Democratic Club was not incuded either.