ciXwin is an X Server implementation for Windows systems with a connection wizard. It is a packaging of X, Cygwin and a collection of related tools to make it a standalone solution ready to use.
X is an architecture-independent system for remote GUI and input, common on Unix-like systems. Cygwin is a Linux-like environment for Windows. It consists of a DLL (cygwin1.dll), which emulates substantial Linux API functionality, and a collection of tools. Cygwin/X is a dedicated project/team taking care of X on Cygwin.