Definition: USENIX

(USENIX Association, Berkeley, CA. Known officially as the Advanced Computing Systems Association, USENIX is a non-profit, membership group of engineers, scientists, technicians and systems professionals founded in 1975. USENIX sponsors workshops and conferences, student programs and awards.

SAGE
The USENIX Special Interest Group for Sysadmins, formerly System Administrators Guild (SAGE), is a high-profile, technical sub-group of USENIX members devoted to the professional development of system administrators.