Open Source Crystal System Software

A POSIX-like x86-64 kernel and userspace written in Crystal. A CPU with x64 support is required to run the OS. The Makefile provides a script that will run QEMU on the kernel. To run with storage, an MBR-formatted hard drive image with a FAT16 partition must be provided in the running directory with the name drive.img. The kernel will automatically boot the main.bin executable on the hard drive, or panic if it can't be loaded.

LavinMQ is a high-performance message queue and streaming server built for efficient message delivery. It implements AMQP 0-9-1 and MQTT 3.1.1, making it useful for applications that need reliable messaging, IoT communication, event processing, and backend service coordination. The server is written in Crystal, which helps it keep memory usage low while supporting high throughput. It is designed to handle very long queues, many client connections, and production workloads with minimal configuration. LavinMQ can be used as a lightweight alternative in RabbitMQ-compatible environments where AMQP-based clients are already common. Its main value is combining speed, low resource consumption, protocol compatibility, and operational simplicity in one open-source broker.