I came across the MaPZone (http://www.mapzoneeditor.com/) texture procedural texture editor. I haven't tried it yet, but it seems to be quite comprehensive. It can export to various bitmap formats, or as a library for their retail ProFX (http://www.allegorithmic.com/?PAGE=PRODUCTS.substance) middleware.
afaik its comercial, isnt it?
No, the middleware is the commercial product.