LVGL (Light and Versatile Graphics Library) is an embedded GUI library written in C, providing a comprehensive widget toolkit (30+ widgets), style system, layout managers (flex, grid, split), animation framework, and multiple rendering backends (software, GPU-accelerated via VG-Lite, NanoVG, OpenGL ES, and hardware-specific backends for various MCU/MPU platforms). It is designed for resource-constrained devices with a small memory footprint (~100kB RAM for typical UIs) and supports a wide range of display drivers (SDL, Wayland, DRM, UEFI, Windows, and many embedded display controllers) and input devices (touch, keypad, mouse, gestures). The library features a public/private header pattern for encapsulation, a configurable build system via Kconfig, extensive Unity-based test suites with screenshot comparison, and a GDB plugin for runtime introspection. It is actively maintained with frequent commits, comprehensive CI/CD, and a large ecosystem of examples and demos.
MCUboot is a secure bootloader for 32-bit microcontrollers, providing signed and encrypted firmware upgrade capabilities. The repository contains the core bootloader library (C) with support for multiple RTOS platforms (Zephyr, Mynewt, NuttX, Mbed OS, Espressif, Cypress), a Python image signing and management tool (imgtool), a Rust-based simulator for testing boot scenarios, and vendored cryptographic libraries (TinyCrypt, Mbed TLS subset, fiat-crypto). The system architecture is a library with platform-specific ports: the common boot logic (bootutil) handles image validation, swap algorithms (scratch, move, offset, direct-XIP, RAM-load), encryption, and fault-injection hardening. Each platform provides flash map, logging, watchdog, and boot entry point implementations. The codebase is highly configurable via compile-time flags, supporting multiple signature schemes (RSA, ECDSA, Ed25519), encryption backends, and upgrade modes. It is not a standalone application but a bootloader intended to be integrated into embedded firmware projects.