Notice: This will get reorganized fairly soon(tm), as it is getting hard to both update and browse.

Blogs, educational

Red Blob Games - Blog about various game dev and compsci topics
Vivonomicon - Embedded focused blog
Embedded Artistry - Embedded blog and knowledge base
thirtythreeforty - Embedded focused blog, mostly embedded linux
Interrupt@Memfault - Blog about embedded firmware development
Game From Scratch - Game development news and knowledge base
CSS Tricks - Good CSS knowledge base
Bit Twiddling Hacks
Real System Failures - Actual electrnics failures that happened to NASA and similar big groups
PhET simulations - Awesome interactive science simulations for education
Academo - Interactive tools for science learning/education
Pink Trombone - Discover how human voice works!
Falstad simulations - Physics simulations
The Genetic Geography of the Brain
Biochemical Pathways - Diagram of the chemical processes in human body
Rockets of Earth - Explore all the rockets
Virus Explorer
Science Discord Network - Discords focused on science
Vim for humans - Efficiently learn vim
The Deadlock Empire - Game that makes you learn and understand concurency
Missing CS semester - Classes that teach you about important, but often not covered topics
The Lost Art of Structure Packing
Google C++ Style Guide
C++ Core Guidelines
How To Use The Slide Rule
VisualAlgo - A great tool that helps you understand how various algorithms work
The Incredible Proof Machine - Learn how to do proofs in logic without having to learn weird languages first!
Developer Roadmaps - Roadmaps on how to become frontend, backend, devops etc.

Interesting things and toys

Awesome - List of awesome lists about interesting topics
Tectonics.js - Tectonics simulator in browser
Music From Outer Space - DIY audio synthesizers
Vulgarlang - Language generator
Pohled ze šaliny - Dashcam videos of Brno public transport
Data Brno - database of open data about Brno
GIS Brno - a lot of map data about Brno
BAM Brno - Brno architecture manual
Kafelénka - Urban exploration of Brno
Správným směrem - Urban exploration of Brno II
bigpixel - Huge high resolution panoramas
Gigapanorama - high resolution panorama of Prague
Silk - Draw funky looking symetric art
Canvas Cycle - Animated pixel art background cycles
PineTime - open source hackable watch
Awesome split keyboards
Awesome console services
Awesome self-hosted
Z80 Explorer - Explore the Z80 processor with a detailed simulator
Visual6502 - Transistor-level simulator of 6502 CPU (and other chips)
shapecatcher - Draw a character and find the unicode of it
Terms of Service; Didn’t Read - Summary of TOS for common services and sites
Keyboard Simulator - Play around with keyboard color schemes and layouts
Virtaul Card Read-Punch - Write Python, Perl, etc. programs on punchcards!
Slide Rule Simulator
Bluestacks - Android emulation for games
eDEX-UI - A fancy SciFi looking terminal emulator

Fun

speak lolcat
Choir
The Auction Game
Random Street View
DAN-BALL
Sandspiel
Gene-Rally
Drawception
Collection of Lenny faces
Collection of japanese emoticons
RetroArch - Emulator frontend
Jargon Generator - If we program the pixel, we can get to the XML bandwidth through the auxiliary RSS sensor!

Libraries

LVGL - Lightweight GUI library for embedded targets
PyViz - List of Python tools for data visualization
COBS - Consistent Overhead Byte Stuffing
Capn’n Proto - Cerealization protocol
ursina engine - Simple Python game engine
Dear ImGui - C++ GUI library
Cinder - Library for creative coding in C++
NanoGUI - Minimalistic GUI widget library for C++ and Python
imgui-plot - plot widget for ImGui
SDL
GLFW
SFML
CAF - C++ actor model framework
GuiLite - lightweight, header only GUI library
uGFX - lightweight GUI library for embedded devices
Kaitai structs - library for describing and parsing binary data structures
Mustache - Simple plain text templating library
OpenCores - Large collection of gateware IP Cores
Ant Design - Web Framework
Tailwind CSS - My favourite CSS framework, utility-first
FastAPI - Python web API framework
HIP - Portable GPU Compute API that runs both on NVidia and AMD with same source code

Programming languages

Clash - Hardware description language based on Haskell
Lua - scripting language designed to be embedded inside larger code bases
Squirrel - high level scripting language, similar to Lua
OpenBSP - CNC Language, alternative to G-code

Tools

Avogadr.io - Molecular symbol creator
HeroMachine 3 - Hero avatar creator
Hero Forge - Miniature creator
Sourcetrail - Source code explorer
Aseprite - Pixel art tool
TikZiT - GUI editor for TikZ graphs
Krita - Open source digital art software
CV-Template - Simple and nice CV templates
Autodesk Sketchbook - Simple, free sketching tool
DevDocs - multiple API documentations in single interface
AsciiDoc - document generation from plain text, Markdown alternative
h5ai - HTTP web server file indexer
tracy - powerful C++(and other) profiler
Ventoy - create multiple bootable USB drives with a single USB
cool-retro-term - Retro terminal emulator
VRoid Studio - 3D character creator
Micro - Modern, simple terminal text editor
CircuiTikZ - Draw eelctrical networks with TikZ
ReactOS - Open source operating system that can run Windows binaries (Reverse engineered Windows)
Visions of Chaos - Fractals toolbox
ZofzPCB - Advanced 3D Gerber viewer
WaveDrom - timing diagram drawing tool
Extraterm - advanced terminal emulator full of features
Privatezilla - Security check of Windows 10
Bloatbox - Remove apps from Windows 10
Umami - open source Google Analytics alternative
Surge.sh - Quick, simple and free/cheap hosting
Alacritty - GPU accelerated terminal emulator
liquidctl - Tool and drivers for controlling liquid coolers and similar
Piper - Tool for setting up gaming mice on linux
OpenRGB - Open source RGB control software
WebPlotDigitizer - Scrape data from image of a plot
4coder - Modern editor based on emacs
Fish shell - Smart, friendly shell
OhMyZSH - Framework for configuring ZSH shell
fzf - Commandline fuzzy finder
LXI-Tools - Tools for controlling scientifing instruments over LAN
tio - Simple TTY Terminal
WireWiz - Create wiring diagrams, document cables and harnesses
gdbgui - GDB frontend in a web browser
wttr.in - Weather reports designed to be curled in terminal
cheat.sh - Curlable cheat sheat
tldr pages - Simple community driven man pages
Homer - static homepage for (home) servers
GreenWithEnvy - Get info and control your NVidia GPU on linux
Cmder - Powerful Windows console emulator
dbdiagram.io - Tool for drawing ER diagrams
REW - Room acoustics analysation software
Starship - Customizable universal prompt for any shell
Obsidian - Knowledge base/personal organization tool
Spectrum Micro-Cap - Industrial grade electronics simulation, recently gone free
WorldPainter - Minecraft world editor
Blockbench - Browser based blocky 3D editor
bat - Modern cat replacement