The goal of the GNU PDF project from its beginning in 2007 was to provide a complete implementation of the emerging ISO standard for PDF, ISO 32000-1. We've had free software PDF viewers for a long time, but at the time most of them didn't support newer PDF features like annotations and forms.

We're happy to report that libpoppler, the most common PDF library on GNU/Linux, has matured its support for these and other PDF features -- a move that means every free software user can have PDF software with capabilities that were until recently exclusive to proprietary software.

The Free Software Foundation maintains a list of high priority free software projects, which are vitally important for a fully free operating system. Previous projects on the list that have been completed include free software support for the RARv3 format (The Unarchiver), a database system for nonprofit organizations (CiviCRM) and now the GNU PDF project.

FSF Europe maintains a list of free software PDF readers for all operating systems. Options can also be found searching for "PDF" in our Free Software Directory.