The Ajax XML Encoder (AXE), developed at the Maryland Institute for Technology in the Humanities (MITH), revolutionizes the production of electronic editions and digital archives. AXE, the first item in MITH's proposed toolkit for the digital humanities, is a web-based tool for "tagging" text, video, audio, and image files with XML metadata, a process that is now a necessary but onerous first step in the production of digital material. With an intuitive, web-based interface, AXE makes this process more efficient and accurate. It also facilitates collaboration in the digital humanities by permitting multiple scholars to work on the same document or archive at the same time from various locations, and tracks all work so that variant versions can be collated and all versions can be archived. The open source AXE provides a free and improved alternative to existing software for tagging all kinds of digital content in an increasingly web-based and multi-medial digital environment.