Compatibility with other devices of similar purpose can be acheived with at least three different ways:
1) alternative device can be pluged-in into spare USB hub slot through USB-RS232 adapter. A software converter of NMEA messages will translate PFLAU/PFLAA traffic alert messages into the input format of the device developed by topic-starter. But this is "read-only", one-way method;
2) second way is reverese-engineering of radio protocol. That was already done before (in 2008) and where published in this newsgroup followed by reaction of manufacturer.
See this thread: https://groups.google.com/forum/#!ms...s/KOoAiKhERhUJ
3) to purchase a license or invite a current licensee to contribute compatibility into this open project;

Any of above can be done then contributed by volunteer who wants to add the compatibility into this project.

Our club's fleet is about 40+ sailplanes and 5 tow planes. Only three of these aircrafts currently carry onboard a Flarm device. Owners are typically keep them switched off because it makes little sense to drawn battery power when majority of traffic is not equipped with Flarm.

For me, personally, I have no plans to spend my own time to develop compatibility with Flarm. ADS-B is comming soon. So any other devices will leave from market within next few years unless they will switch onto ADS-B standard.
Thus operation on ADS-B is the way where the project should go.

2-way ADS-B USB plug-in for this device is a module that worth to be developed within next couple years.