unfortunately we can't offer linux suport at the moment
the protocol can't be opened as it's under NDA with TI
The MSP GCC wiki
has information about making the TI USB programmer function under linux using the Windows GDBProxy.
The way it works is the TI USB programmer is first made to display as a standard serial port under Linux. The TI programmer requires a firmware is loaded to it over the USB interface. This is proprietary and closed source. Once the firmware is located and stored where the linux kernel expects it, plugging in the TI USB programmer makes it show up as /dev/ttyUSB0
Now that the programmer is accessible, we can run GDBProxy and it's MSP430.dll using WINE. You already have replacement DLLs that work with MSPGCC's GDBProxy. All you need to do is make your MSP-JTAG-TINY show up as a serial port on linux, and WINE can handle the rest. There's a good chance this is possible without violating your NDA.
If it's not possible, you could distribute source code for a kernel module that contains a binary blob. The binary blob contains the parts that you aren't allowed to share and the rest is a wrapper that makes it work with the kernel. Users could 'make && make install' this on their systems and would need to re-install it everytime they update their kernel. This could not be included into the mainline kernel source in this form, but could be available from your website.
Anyway that you can make the programmer show up as a ttyUSB device would be greatly appreciated by your customers.