OpenSkin Designer v3.0.0.0
https://github.com/iMaxxx/OpenSkin-Designer
I installed (well just extracted the zip) and just started playing with it. It loaded a few skins without error and seems functional, but I haven't done much with it. Is there something better that people are using? I am not interested in starting some new skin from scratch, just making a few changes to some existing skins (for alien2.)
OpenSkin-Designer-master.zip