I have sent patches with KT-LINK interface driver (FT2232H based, full-featured, low-cost, SWJ capable design by Krzysztof Kajstura) working in JTAG mode for UrJTAG low-level access software utility with GNU license. I have also created a dedicated fork of UrJTAG for LibSWD integration, which is open and available at http://repo.or.cz/w/urjtag/libswd.git. When the job on LibSWD error handling is finished and fully functional with OpenOCD, I will make a release of LibSWD that will be also integrated with UrJTAG using git submodule mechanism just as in my OpenOCD+LibSWD fork :-)