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...
Substance Designer - Substance Designer is a node-based non-destructive application for material authoring.
TextureLab - Free, Cross-Platform, GPU-Accelerated Procedural Texture Generator.
TextureWorks - AI-based, seamless texture generation and re-scaling tool for the desktop.
Substance Alchemist - The material enthusiast's toolbox