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May 08, 2004
ChorusOS and Jaluna
Sun acquired Chorus Systems in late 1997, apparently with the notion of using the Chorus microkernel as the basis for a Java operating system, but also to help Sun expand into the Network Equipment Provider market. The Chorus microkernel offers real time capability, hardware abstraction, and virtual memory. Above the configurable microkernel layer, Chorus provides support for distributed systems and different operating system personalities. In other words, you can have an incarnation such as ChorusOS 4.x, with a POSIX personality based on Free BSD, that gives you API compatibility with other UNIX systems, making it easier for Network Equipment Providers to have applications running all the way from the base station controller into the large backend systems, using the same code. Other incarnations provided PSOS APIs, for example. This has probably enabled compatibility with VxWorks as well, and of course means that you can port Linux on top of the microkernel.
At the end of the last century, the Network Equipment Provider market was expanding quickly. Sun folded ChorusOS into the Netra HA Suite for customers in this market. Netra HA Suite provides a level of API compatibility between ChorusOS and Solaris systems that lets NEPs write once, more or less, for applications running across their network infrastructure. Netra HA Suite also provides a distributed, container-based architecture for high availability across the network infrastructure. In other words, NEPs writing to Netra HA Suite can have applications fail over quickly and statefully from one hardware node to another, over the network, no matter what.
When the NEP bubble popped, and Sun was not in the market for devices, the folks who invented the Chorus microkernel went on to found Jaluna. Jaluna appears to have opened the source for the basic system, gone more heavily into Linux, and aimed at providing more functionality at the high end. An interesting historical wrinkle in all this: Tilly Bayard-Richard managed to take all the documentation we wrote in or had moved to Sun's SolBook format, a subset of DocBook, and use open source tools to rebrand and republish it without extensive modification to the content. You can see the results here at Jaluna.
Posted by Mark at May 8, 2004 07:13 AM