You can check out my library riko [1, 2]. While it doesn't have a slick GUI, it does support most of the original yahoo pipes (including xpath [3] and regex [4]).

[1] https://github.com/nerevu/riko

[2] https://www.youtube.com/watch?v=bpn2G3TAAYY

[3] https://github.com/nerevu/riko/blob/master/riko/modules/xpat...

[4] https://github.com/nerevu/riko/blob/master/riko/modules/rege...