VxWorks ®

VxWorks is a real-time, UNIX ® -like portable operating system primarily intended for embedded applications. It is produced and supported by Wind River Systems, Inc. It consists of a multitasking kernel and a suite of libraries providing features like:

Semaphores and message queues;
Linked lists;
loadable device drivers (including network drivers);
UNIX-style Internet protocol stack/services (IP, UDP/IP, TCP/IP, NFS, etc.);
Filesystem support;
and more.

It is, however, single-user. It is supported on various CPU architectures, including Motorola 680X0-series, PowerPC, SPARC, Intel i960, etc. Its most popular use to date seems to be in VME CPU boards.

Licensing

VxWorks is a portable operating system, so an end user frequently purchases the development system from Wind River, and either purchases or creates a "board support package" which consists of board-specific software and configuration parameters. Many board support packages exist for popular commercial boards, and many board vendors create these and sell them as Value Added Resellers of VxWorks. The type of license you need in order to operate the software depends upon how you obtain a particular board support package. There are various types of license, including:

Development License: allows creation of VxWorks board support package and any user software to run on the target
Target License: allows use of VxWorks on a single board

If VxWorks came with a commercial board you purchased, then you implicitly own a target license for that board, meaning that you can run VxWorks on that board. This is because the vendor is paying a fee as a Value Added Reseller.

VxWorks is a registered trademark of Wind River Systems, Inc.

UNIX is a registered trademark of AT&T (and/or Novell Systems?)