The Ygor system was designed for control and monitoring of the many pieces of hardware that make up the GBT. In order to do this Ygor must be able to command (i.e. setup system parameters) and control (i.e. make an observation happen) these devices in an efficient manner. Ygor also provides monitoring for logging purposes, and an alarm/messaging system for those un-expected failures.
The M&C system is written in C++ programming language. This allows a low level of programming to avoid the use of extensive language compilers that would tend to slow down the process of instruction execution. The programming is written in modules, also called libraries, which are standardized between devices to keep programming efforts to a minimum as well as making it very flexible. By structuring the software this way, devices can be added or removed from the system without effecting the system as a whole.
The operating system for Ygor is VX Works. This is considered a "real time" operating system and is usable across all computing platforms, thus enhancing the capability of the M&C system to interface to custom devices.
These programs run continuously on the telescope's control computers and can be thought of as the operating system for the telescope. The programs are initiated automatically whenever the computers are rebooted. It is necessary for these programs to have some astronomical data and algorithms, but by and large they are designed to control and monitor telescope hardware independently of any astronomical considerations. In the dialect of computer science these are server programs, i.e., they provide services, i.e., a clean software interface that allows other programs all the control and flexibility they need to get maximum use of the telescope.