OpenPAM is a BSD-licensed implementation of PAM used by FreeBSD, NetBSD, DragonFly BSD and macOS (starting with Snow Leopard), and offered as an alternative to Linux PAM in certain Linux distributions<sup>[which?]</sup>.
OpenPAM was developed for the FreeBSD Project by Dag-Erling Smørgrav and NAI Labs, the Security Research Division of Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research program.
On 1 January 2008, OpenPAM was one of eleven projects selected by Coverity for promotion to Rung 2 of their DHS-funded Open Source Hardening Project, which tracks bugs found in open-source software by Coverity's Prevent static program analysis tool. On 23 September 2009, OpenPAM was promoted to Rung 3, along with Ruby, Samba and Tor.