|   | Definition: |   | 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]  |