Apatosaurus is a new web platform initially developed for managing digital collations of Greek New Testament manuscripts. At present, it may be used to create, visualize, analyze, and publish any left-to-right edition. (1) Collation Creation and Editing: To maintain interoperability with other tools such as the ITSEE Collation Editor, a user may import a TEI formatted collation file, make edits, and export the data as TEI XML. Alternatively, a user may construct a collation from scratch by providing a basetext, readings, and witnesses. The collation data is stored in a relational database and every part of the collation may be edited. A history of changes is recorded so that a user may revert to previous versions of a reading. (2) Visualization: Apatosaurus provides an intuitive layout for visualizing and exploring collation data. (3) Analysis: Apatosaurus includes a full implementation of the CBGM by providing a complete user interface for Joey McCollum’s open-cbgm library. It is possible as an independent researcher or student to create a digital collation and apply the CBGM to it. Teachers and educators may be especially interested in the pedagogical implications. (4) Publication: Users may publish an apparatus and make it public. (5) Technology: Apatosaurus is open source, free to use, and available to anyone. The main app is programmed with Python and Django and the database is Postgres. https://apatosaurus.io