Abstract
Since version 7.2 the Mizar system produces quite detailed XML-based semantic description of Mizar articles during their verification. This format is now used natively for most of the processing done by Mizar, e.g., also for the whole Mizar internal database.
The main motivation for switching to this XML-based representation is to make semantic communication with Mizar and presentation of the MML more accessible to a variety of external tools and systems. This article briefly describes this format and its current implementation, and shows examples of its usage.
These examples include presentation of linked Mizar articles in modern XML-capable browsers like Mozilla, authoring assistance in the Mizar mode for Emacs, and experiments with XML-based querying languages like XQuery over the Mizar Mathematical Library loaded into a native XML databases like eXist. This work makes the currently largest repository of formal mathematics available to many kinds of applications and experiments.