TextureLab - Free, Cross-Platform, GPU-Accelerated Procedural Texture Generator.
Material Maker - Cross-platform, procedural texture generation tool.
Filter Forge - On the surface, Filter Forge is just a Photoshop plugin, a pack of filters that generate textures...
PixPlant - A complete solution for repeating textures and 3D maps. Save a lot of texturing time with PixPlant!
Substance Designer - Substance Designer is a node-based non-destructive application for material authoring.
GraphicDesignerToolbox - Graphics editor for composing textures, buttons, logos, icons.