AUTOMATIC1111 is a username used by a developer who has created a web user interface for Stable Diffusion, a deep learning-based image generation technique. The user interface allows users to generate images by inputting prompts and adjusting various settings, such as the CLIP skip option, which controls how early the processing of the prompt by the CLIP network should be stopped. AUTOMATIC1111's web user interface also includes features such as a checkpoint merger for combining two or more models, an Interrogate CLIP button for guessing the prompt of an uploaded image, and a Train page for training models. To use AUTOMATIC1111, users must first install it on their computer by cloning the repository from GitHub and running the web user interface in a web browser.