Flint

Description
Flint uses a variety of libraries and tools, as well as internal logic, to validate files against a configurable policy. It uses: More detail is provided in this blog post: Introducing Flint
 * Apache PDFBox
 * Apache Tika
 * Calibre
 * EPUBCheck
 * (Optionally) iText - note that this library is AGPL3 licensed

Development Activity
https://github.com/openplanets/flint/commits/master.atom