(1) See
Pentium 4.
(2) An open source special-purpose network programming language from the P4 Consortium that is used to control packet forwarding in software-defined network (SDN) devices (switches, routers, etc.). P4 compilers are available for numerous P4 "targets," which are the chips that perform the actual packet forwarding. Devices that execute P4 instructions are also called "P4 switches." See
software-defined networking.