The VMEbus standard uses pin and socket connectors. This is superior to edge connections in that the connection is not exposed to humidity and other environmental conditions. It is a more expensive way of doing things, but offers longer times before failure.
A VMEboard is either a 3U (160 x 100 mm) or a 6U size (160 x 233.35 mm). These sizes correspond to the Eurocard standard for board modules and card cages. Eurocard is a popular format used by many different busses including CompactPCI. This popularity makes the materials needed for cage assembly inexpensive and easy to obtain.
The nature of Linux is in its user supported and freely available format. The number of people using Linux is growing. The number of people contributing to the continued development of the Linux software base is growing. It is unfair to state that Linux is a good value because it is available for little to no charge. Linux is a good value because it works.
There are those who say that Linux us an unstable operating system. It is true that the new Linux kernels in development are experimental and should not be relied on for critical applications. However, stable versions of the Linux OS are always available and provide very stable operation. VMELinux is always based on the stable versions of the kernel source; Today's stable kernels are the 2.0.X series.
Because so many people are developing Linux, you do not have to wait long for improvements, fixes or new features to become part of the Linux distribution.