* [Stirling PDF v3.1.0](https://github.com/Stirling-Tools/Stirling-PDF) – PDF platform providing desktop, web, and self-hosted deployments with signing, redaction, conversion, OCR, and automation.

* [HexaPDF REL\_1\_11\_1](https://github.com/gettalong/hexapdf) – Versatile library for creating and manipulating PDF files in Ruby.