ChibiOS/RT is a free and efficient RTOS designed for deeply embedded applications. It offers a comprehensive set of kernel primitives and supports many architectures: ARM7, Cortex-M0, Cortex-M3, Cortex-M4, PowerPC e200z, STM8, AVR, MSP430, ColdFire, H8S, x86.
xinco [eXtensibe INformation COre] is a powerful Web-Service based Information and Document Management System (DMS) for files, text, URLs and contacts, featuring ACLs, versioning, full text search, an FTP-like client (easy install, J2EE+MySQL/PostgreSQL)
AO RTOS is small real time OS based on Active Object concurrency model
AO-RTOS is a pure object-oriented small footprint real-time operating system for embedded devices. The project is using Active Object (or Actor) concurrency model and finite state machine (FSM) design template as implementation base.
Engineering Calculator Suite
The definitive DASH7 firmware project
OpenTag is a full-featured communications stack for DASH7 Mode 2 (ISO 18000-7.4). It is intended to run on embedded HW, especially RF SoCs, but it can be ported to almost anything. OpenTag's main feat is its large featureset, but small footprint. Also see the official OpenTag website: http://www.indigresso.com/wiki/doku.php