Stablematic is a web platform that allows users to run Stable Diffusion and machine learning models in a browser using high-performance GPUs. Key features of Stablematic include the ability to generate videos and animations using text prompts, merge and train image models, access pre-installed plug-ins, and a simple pricing system. Additionally, Stablematic offers dedicated 1-on-1 feature support, pre-installed models, and API access.