Sites like fredrikj.net

A Python plotting library documentation site for Matplotlib, covering static, animated and interactive data visualizations

Yummy Melon hosts Scrim and Captee, macOS tools for Emacs and Org, plus Charles Choi's "notes from /dev/null" blog on Emacs

COIN-OR news blog on open-source operations research software, announcing the COIN-OR Cup awards and foundation board notices

Org Mode for GNU Emacs: a plain-text major mode and project site for notes, to-do lists, planning and literate programming

A personal blog by Matt Buffett on chess programming, Rust, book reviews and other topics, written in English

Personal blog and portfolio of Eevee, covering writing, drawing, games, toys and dev logs, with an explicit-content marker

The NetBSD Project's home site for its free, portable Unix-like operating system, with documentation, platform lists, news and downloads

The official website of Universidad de los Andes, a Colombian university, with news, events, research and fundraising campaigns

Protesilaos (Prot)'s personal website on GNU Emacs packages, Linux, PGP keys, coaching and writing, by Prot Stavrou

Sioyek, a PDF viewer for technical books and research papers, with search, bookmarks and highlights

OpenSCAD is free software for creating solid 3D CAD models by coding, with news and gallery pages

SciPy, an open source Python library of algorithms for scientific computing, covering optimization, integration, interpolation, statistics and differential equations

200ok is a Swiss software company building publishing infrastructure, newsroom tools and open source products such as aleph DAM and organice

Syncthing, an open-source continuous file synchronisation tool, with project donation and foundation information pages

vanheusden.com is a personal software project page by Folkert van Heusden listing audio, networking, games, chess and Go tools

NumPy project website: the official home of the open source Python library for numerical computing and N-dimensional arrays

The LaTeX Project's website on LaTeX, the document preparation and typesetting system for technical and scientific publishing, with downloads, bug reporting, help and licence text

LibrePCB, a free open-source electronic design automation suite for drawing schematics and designing printed circuit boards, with a blog and documentation

Piper Haywood's personal notebook blog on software engineering, design, health with lupus, travel, and assorted everyday notes

The official home of the Haskell programming language, covering its compiler GHC, build tool Cabal, installer GHCup and community resources

BleachBit, an open-source disk cleaner and file shredder for Windows and Linux systems, with its help and documentation pages

VirtualGL, an open-source project providing GPU-accelerated 3D rendering to remote X11 clients, with news, documentation and package repositories

UBports, a community site on Ubuntu Touch, an open source Linux mobile operating system, with FAQ, apps and jobs

Falcon, a minimal Python web framework for building fast REST APIs, documented on its project site

Colin Percival's blog Daemonic Dispatches on FreeBSD, Tarsnap backups, security and miscellaneous musings, with a Route 53 Files tool

A cross-platform C library and command-line tools for communicating with iOS devices, developed as free open-source software

Free software projects by Eskild Hustvedt, including wwine, gpgpwd, SSHMan and BoringSSG, on a personal project page

Xe Iaso's personal website: blog essays, talks, and Twitch VOD archive on making technology understandable, by a technical educator

Asciidoctor, an open source Ruby text processor and toolchain converting AsciiDoc to HTML5, DocBook, PDF, and EPUB, with documentation and news

Zompist.com: Mark Rosenfelder's personal site on conlanging, with an invented language grammar and a Minimalist grammar random-sentence generator

A collection of free image processing algorithms and documentation for the scikit-image toolbox in Python

Software and writing by Michael R Sweet, covering system monitoring tools, Mini-XML, and related programming projects

A Firefox-based web browser project, built by a group of developers and designers focused on productivity and privacy

A free community UNIX shell server, est. 1987, offering shell accounts, email, IRC, gopher, and user home pages