P4 is an 'open', 'target independent' language specification
Supported across heterogeneous targets - CPUs, FPGAs, GPUs, NICs , Network Processors (Barefoot Totino) from different vendors
P4 brings 'programmability' to the data plane.
Implies a 'software' development approach rather than a traditional 'hardware' development approach. Barefoot Networks Totino LSI allows programmability of the the ASIC pipeline