Salvo™ is a full featured, cooperative, event driven,
priority based, multi-tasking RTOS with highly efficient
memory utilization. It is ideally suited for use on
Microchip PICmicro® devices. Written in C, it is very
easy to use, employing standardized RTOS methods
and terminology.
http://ww1.microchip.com/downloads/en/AppNotes/00777b.pdf
Pumpkin: Salvo, the RTOS that runs in tiny places on HE
Salvo™ is the first Real-Time Operating System (RTOS) designed expressly for very-low-cost embedded systems with severely limited program and data memory. With Salvo, you can quickly create low-cost, smart and sophisticated embedded products
Salvo was designed from the ground up for use in microprocessors
and microcontrollers with severely limited resources, and will
typically require from 5 to 100 times less memory than other
RTOSes.