Popular free and open source PDF editors include LibreOffice, PDFSam, PDFedit, ONLYOFFICE and Xournal++.

The PDF (portable document format) standard was created in the 1990s by Adobe cofounder John Warnock to make it possible for people to share reliably formatted documents across a wide range of platforms. It became an open ISO standard in 2015. Today, you can save documents as PDF files from many applications (e.g., exporting a document as a PDF from Word) and edit PDF files (e.g., using a PDF editor). Depending on the tool you use, you can also password protect, encrypt and digitally sign PDFs.

PDFs are "the unsung heroes, the workhorses in the background, quietly enabling businesses to streamline communication, enhance accessibility, and ensure consistency," said DeeDee Kato, vice president of corporate marketing at Foxit, which offers PDF and eSignature products and services.

There are several reasons for saving documents in PDF format. These include: