1. Scheme Object System.

2. An infamously losing text editor. Once, back in the 1960s, when a text editor was needed for the PDP-6, a hacker crufted together a quick-and-dirty "stopgap editor" to be used until a better one was written. Unfortunately, the old one was never really discarded when new ones (in particular, TECO) came along. SOS is a descendant ("Son of Stopgap") of that editor, and many PDP-10 users gained the dubious pleasure of its acquaintance. Since then other programs similar in style to SOS have been written, notably the early font editor BILOS /bye'lohs/, the Brother-In-Law Of Stopgap (the alternate expansion "Bastard Issue, Loins of Stopgap" has been proposed).

3. The PDP-10 instruction to decrease a value. Oppose AOS.

[Jargon File]