WebMagick makes image collections available on the Web. It recurses through directory trees, building HTML pages, imagemap files, and client-side/server-side maps or HTML tables to allow the user to navigate through collections of thumbnail galleries. Using JavaScript, HTML tables and cookies, WebMagick can also allow the viewer to configure how they view the gallery. The primary focus of WebMagick is performance. Image thumbnails are reduced and composed into a single image to reduce client accesses, reducing server load and improving client performance. Everything is pre-computed. During operation WebMagick employs innovative caching and work-avoidance techniques to make successive executions much faster. WebMagick has been successfully executed on directory trees containing many hundreds of directories and hundreds of thousands of images ranging from tiny icons to large JPEGs and PDF files.