Xyd is a program that was developed at the IfA to control the Xy stage for the 88" telescope. Xxy is a graphical user's interface to xyd.
Xyd connects to Galil hardware using a telnet interface, and listens to a TCP/IP port for remote commands. It is fully controllable via the network interface. Multiple connections to xyd are permitted and any or all may send commands or request information. There is an interlock system, that will prevent multiple commands from being sent to xyd at the same time. There is nothing that will keep different users from interleaving commands.
Xysim is a standalone program that simulates the Galil hardware. It is not a fully functional simulation, but does provide enough functionality to test xyd.
Tcssim is a standalone program that simulates the TCS hardware. It is far from a fully functional simulation, but does provide enough functionality to test xyd.
Xxy is a graphical user interface to xyd.
Libxy.a and libxy.so are libraries that contain functions that simplify the process of connection to xyd. Although it is certainly possible to communicate with xyd via other mechanisms, users are strongly encouraged to use the provided library, or the Tcl library which is built on the provided library.
Xyd, xysim, tcssim, libxy.a, and libxy.so are written in C. The C code is intended to be very portable, and can be compiled on Solaris, Linux, and FreeBSD. The client applications and libraries can be compiled on Sun OS with minor modifications.
Xxy is written in Tcl/Tk. It have been tested with 8.3.x, though they are intended to work with other releases.