Clear back in Bus Pirate firmware v0c there was a simple JTAG programmer called an XSVF player (PDF). XSVF is a set of instructions that tell a programmer how to wiggle pins in such a manner as to enter the firmware into a JTAG device. The v0c programmer wasn’t very user friendly, and involved dumping a binary file into the terminal.
The XSVF player is back as a new bonus firmware. We also whipped up a PC utility for loading XSVF files directly from the command prompt.
We programed an XC9572XL and XC2C64A using XSVF programming files exported from the Xilinx Impact utility. It isn’t limited to Xilinix chips though. There are utilities that convert normal SVF files from any chip vendor into compressed XSVF files. If you test it please let us know if it worked.