FLTK - Fast Light Tool Kit - https://github.com/fltk/fltk - cross platform GUI development

High-quality QR Code generator library in Java, TypeScript/JavaScript, Python, Rust, C++, C.

https://play.google.com/store/apps/details?id=com.mauriciogior.openqrcode

Android USB host serial driver library for CDC, FTDI, Arduino and other devices.

An open source cross-platform USB stack for embedded system

Fixed-point base 2 logarithm algorithm implementation in C; includes added base e and base 10 support, too.

Small portable AES128/192/256 in C

Firmware Analysis Tool

WebUSB Device Firmware Upgrade example

Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc, PowerPC, RiscV, S390x, TriCore, X86)

Capstone disassembly/disassembler framework for ARM, ARM64 (ARMv8), Alpha, BPF, Ethereum VM, HPPA, LoongArch, M68K, M680X, Mips, MOS65XX, PPC, RISC-V(rv32G/rv64G), SH, Sparc, SystemZ, TMS320C64X, T…

Free and open implementation of the CMSIS-DAP debugger firmware

Simple starter projects for bare-metal MCU development

Website for pid.codes

Free USB Stack for PIC 16F, 18F, 24F, and 32MX Microcontrollers