See wiki/FutureProtocol. URFP may be used to talk to UrJTAG through serial links (including RS232, USB and Ethernet), sockets, ...
While implementing the server, which will actually be a new application (like jtag shell) using the rest of UrJTAG as a library, things like global mechanisms for configuration, debug output etc. will be adressed too.
The first step is to export the cable* functions, in order to work out the details of the protocol for efficient execution of low level tasks.
Closing as 'wont-fix' here. URFP is being actively developed and may soon become public but detached from UrJTAG project