ChorusOS is a microkernel real-time operating system designed as a message passing computing model.
[2] Over time, development effort shifted away from distribution aspects to real-time for embedded systems.
[3] In 1997, Sun Microsystems acquired Chorus Systèmes for its microkernel technology, which went toward the new JavaOS.
The founders of Chorus Systèmes started a new company called Jaluna in August 2002.
Jaluna-1 is described there as a real-time Portable Operating System Interface (RT-POSIX) layer based on FreeBSD 4.1, and the CDE cross-platform software development environment.