ppp(4) on OpenBSD

The text 3d59cfd62ae2, as OpenBSD 5.2, OpenBSD 5.1, OpenBSD 5.0, OpenBSD 4.9, OpenBSD 4.8, OpenBSD 4.7, OpenBSD 4.6, OpenBSD 4.5 shipped it.

Point-to-Point Protocol network interface