Mm-papilio is a project mainly written in VERILOG and VHDL, it's free.
milkymist on papilio
milkymist papilio port
cd mm-papilio/tdc-core/demo/tools PATH=/opt/rtems-4.11/bin:$PATH make
cd mm-papilio/tdc-core/demo/software/libbase PATH=/opt/rtems-4.11/bin:$PATH make
cd mm-papilio/tdc-core/demo/software/bios PATH=/opt/rtems-4.11/bin:$PATH make
cd mm-papilio/tdc-core/demo/boards/spec/synthesis PATH=$PATH:/opt/Xilinx/12.3/ISE_DS/ISE/bin/lin make -f Makefile.xst clean PATH=$PATH:/opt/Xilinx/12.3/ISE_DS/ISE/bin/lin make -f Makefile.xst
sudo $HOME/install/bin/papilioloader -f build/system.bit