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DeveloperChorus Systèmes
Sun Microsystems
OS familyPOSIX
Working stateDiscontinued
Source modelClosed-source (pre-v5)
Open source (v5)
Initial release1979; 45 years ago (1979)
Latest release5.1 / 2011; 13 years ago (2011)
Marketing targetEmbedded systems
Available inEnglish
Platformsx86, 680x0, PowerPC, SPARC, ARM, MIPS
Kernel typeMicrokernel real-time operating system
Succeeded byVirtualLogix C5

ChorusOS is a microkernel real-time operating system designed as a message passing computing model. ChorusOS began as the Chorus distributed real-time operating system research project at the French Institute for Research in Computer Science and Automation (INRIA) in 1979.[1] During the 1980s, Chorus was one of two earliest microkernels (the other being Mach) and was developed commercially by startup company Chorus Systèmes SA.[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.[4] Sun (and henceforth Oracle) no longer supports ChorusOS. The founders of Chorus Systèmes started a new company called Jaluna in August 2002. Jaluna then became VirtualLogix, which was then acquired by Red Bend in September 2010. VirtualLogix designed embedded systems using Linux and ChorusOS (which they named VirtualLogix C5). C5 was described by them as a carrier grade operating system, and was actively maintained by them.

The latest source tree of ChorusOS, an evolution of version 5.0, was released as open-source software by Sun and is available at the Sun Download Center.[5] The Jaluna project has completed these sources and published it online. 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. ChorusOS is supported by popular Secure Socket Layer and Transport Layer Security (SSL/TLS) libraries such as wolfSSL.

See also


  1. ^ Coulouris, George; Dollimore, Jean; Kindberg, Tim (1994). Distributed systems: concepts and design. Addison-Wesley. pp. 566–79. ISBN 978-0-201-62433-5. Retrieved 2 December 2012.
  2. ^ Doeppner, Thomas W. (20 December 2010). Operating Systems In Depth: Design and Programming. John Wiley & Sons. p. 36,145. ISBN 978-0-471-68723-8. Retrieved 29 November 2012.
  3. ^ Gien, Michel (1995). Evolution of the CHORUS Open Microkernel Architecture: The STREAM Project. FTDCS '95 Proceedings of the 5th IEEE Workshop on Future Trends of Distributed Computing Systems. IEEE Computer Society. p. 10. Retrieved 2 December 2012.
  4. ^ Saulpaugh, Tom; Mirho, Charles (January 1999). Inside the JavaOS Operating System. Java series. Addison-Wesley. p. XIII. ISBN 0-201-18393-5. OCLC 924842439.
  5. ^ "Sun Download Center". Oracle. Archived from the original on 6 October 2011.