Bus Blaster v2 now supports goJTAG via a new PicoTAP-compatable buffer. goJTAG is an open source GUI for experimenting with JTAG devices:
goJTAG software allows users to study boundary-scan techniques, to carry out their own experiments, to perform diagnosis, and much more. The software environment comes with a built-in example project, and users can create their own projects with descriptions of boards, chips, cluster logic, and so on.
More about the PicoTAP buffer here, upgrade instructions here, download it here. Thank you roglio for the suggestion.