Sites like throwtheswitch.org

MSYS2 is a software distribution and build platform for Windows providing Unix-like tools, compilers and package management documentation

PHPUnit project website by Sebastian Bergmann covering the PHP testing framework, its releases, documentation, sponsors and community events

Ogre3D, an open source C++ 3D graphics rendering engine with news, community forums, a legacy wiki and support

Meeting C++ news site and blog on the C++ programming language, covering its conferences, training, books, jobs and community

Embedded, a podcast by Elecia White and Christopher White on engineering careers, embedded systems, and the lives of makers

A documentation site for pytest, the Python testing framework, with a list of talks, books and tutorials about it

PlantUML, an open-source tool that draws UML diagrams from simple text descriptions, with a Q&A forum and German edition

Thor Vector Graphics (ThorVG), an open-source lightweight vector graphics engine and project site with release notes by Hermet Park

BeagleBoard.org is an open hardware single-board computer project offering documentation, forums, books and support for makers, educators and developers

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

An English-language electronics tutorial and notes site by mbedded.ninja covering PCB bring-up, circuit design, embedded systems and firmware topics

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

An online C++ compiler and shell where users run and share C++ code snippets in the browser

Kivy, an open-source Python framework for building cross-platform GUI apps, with a project blog, about page and documentation

Pocoo, a former team of open source developers behind Python projects Flask, Sphinx, Jinja, Werkzeug and Pygments

pqxx.org is a personal software project site by Jeroen Vermeulen hosting libpqxx, a C++ PostgreSQL client library, plus other open-source tools

A personal blog by Jeff Geerling on software development, Raspberry Pi and maker hardware, and open source tech news

JUnit, a open-source testing framework for Java and the JVM, with documentation, release notes and project information

Godot Engine, a free open-source 2D and 3D game engine with a project blog and forum, with news by Thaddeus Crews and others

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

async-std project site documenting the Rust async standard library, with API docs, project status and contribution guidance

probe-rs is an open-source embedded debugging and flashing toolkit for microcontrollers, documented on its project website

Babel, an open-source JavaScript compiler project with documentation, a browser REPL and a team page, converting modern JavaScript to older-compatible code

The Rust Programming Language project's official site for the Rust systems programming language, with documentation, learning resources and community pages

The International Obfuscated C Code Contest site: rules, entries, winners and FAQ for a yearly C programming contest, by Landon Curtis Noll and Simon Cookson

WebdriverIO API reference documentation for the WebdriverIO browser and mobile test automation framework's commands and protocol bindings

Personal home page of Eric S. Raymond hosting his open-source software, FAQs, essays and the Retrocomputing Museum

Hackaday.io, a community platform where makers publish and share open hardware development projects and build logs

A French-language project page for Armbian, an open-source Debian and Ubuntu Linux distribution for ARM single-board computers

The V programming language, a compiled open-source language site with documentation, comparisons and a compiler for maintainable software

Mock Service Worker, an API mocking library for browser and Node.js JavaScript, with documentation and guides for intercepting network requests

Ramda, a documentation site for a practical JavaScript functional programming library and its function reference

Appium documentation: an open-source software project for UI automation of mobile, browser and desktop apps

A personal website by Thomas Leitner, blog and projects on Ruby libraries, PDF tools, benchmarks and privacy

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

Autodesk's corporate site selling 3D design, engineering, construction and media software such as Fusion, Revit and Forma

Free embedded systems tutorials, articles and projects on firmware, microcontrollers and DSP, by engineer Khaled Magdy

A news blog on embedded systems, maker boards and single-board computers such as Raspberry Pi and Arduino, run by CNX Software Limited

A project website for PyPy, an alternative implementation of the Python programming language with a just-in-time compiler

The aiohttp.org site is the documentation and project page for aiohttp, an asynchronous Python HTTP client and server library built on asyncio

A design and development agency that builds web and mobile products, with case studies and services from thoughtbot

The Nim Programming Language site: documentation, downloads, FAQ, blog and donation pages for the statically typed, compiled systems language Nim