I have for quite some time been attending LARP where Lasertag is used for the combat system. I now participate in games which have two incompatible systems, the UKLTA which uses a proprietary development (Data-over-Tag) of the early Worlds of Wonder system and Humanity Ascendant which uses commercial equipment from the Russian company LaserWar. LaserWar is compatible with the MilesTag system with a few additions for game admin.
For quite some time I've wanted to have a play with time LaserWar kit to see if I can throw some code together that works with it and I finally got round to borrowing some.
MilesTag is simpler than DoT and it didn't take long to update my Arduino library for doing Lasertag so it can both send and receive Laserwar/MilesTag hits. Sending LaserWar game admin codes would also be possible, they're just differently formatted, sometimes longer IR packets.
Sadly I can't make this open source as the packet format for UKLTA DoT is proprietary, but I might strip out the MilesTag parts separately.