This is a XC9572XL-10VQG44C PLD soldered to a proto-advantage PA-0093 header and wired up for programming as described by Tom C. Hayes in Learning the Art of Electronics. PLDs are useful for implementing combinational and sequential logic where speed is important in a specific application.
Here is a tutorial for installing Xilinx and programming the XC9572XL. This was done on an old Windows XP computer I had laying around. I could not get my programming pod to work with Windows 10.
