AsciidoctorFast text processor for the AsciiDoc markup language, turning plain-text documents into HTML, PDF, EPUB and man pages. A cornerstone of docs-as-code: documentation stored as versionable, future-proof plain text.calibreThe complete e-book toolkit: library management, format conversion between dozens of e-book formats, device synchronisation, metadata editing and a content server. Kovid Goyal's project has become the indispensable tool for keeping personal digital libraries alive and portable.GNU TeXmacsScientific editing platform producing publication-quality documents with live mathematics, interfaces to computer algebra systems and structured editing — inspired by TeX and Emacs but sharing code with neither.GnuCashDouble-entry accounting software for personal and small-business finance — accounts, invoices, reports and bank imports, maintained continuously since 1997. Financial records are exactly the kind of data that must outlive any vendor.LibreOfficeFull-featured free office suite — writer, spreadsheets, presentations, drawing, databases and math — and the home of the OpenDocument standard formats. Forked from OpenOffice.org in 2010 under The Document Foundation, it safeguards decades of documents from format lock-in.LyXDocument processor built on the WYSIWYM principle — "what you see is what you mean" — combining a friendly editing interface with LaTeX's typesetting rigour underneath. Theses and books have been written in it for three decades.OkularKDE's universal document viewer for PDF, EPUB, DjVu, comics and more, with annotation, form filling and digital signatures — the first software ever awarded the Blue Angel eco-label for resource efficiency.PandocThe universal document converter, translating between dozens of markup and document formats — Markdown, LaTeX, DOCX, EPUB, HTML and more. Written in Haskell by philosopher John MacFarlane, it is the Rosetta stone of document preservation.TypstModern typesetting system compiling readable markup to print-quality PDF with instant preview — a fresh, fast alternative to LaTeX whose compiler is fully open source.zathuraMinimal keyboard-driven document viewer for PDF, DjVu, PostScript and EPUB, with vim-style navigation and a plugin-based rendering backend. A small tool that does one thing precisely.
