There is life left in P25, perhaps the first somewhat popular digital voice mode on Amateur Radio VHF/UHF. The life comes from a linking system that David Krauss NX4Y introduces at the 2016 DCC. He calls it P25NX - Network Exchange.
The P25 mode started in Public Safety radio in the mid '80's. After about 10 years, those guys say their radios are due for replacement. Hams bought the trade-ins and put them on the ham bands. But the repeaters were isolated islands. D-STAR became more popular because repeaters were linked, bringing in traffic from around the country or world. P-25 is about to have even more cheap equipment on the market as they migrate to Phase 2, and David's link system could make P25 a competitive mode in ham radio again.