RSTS (/ˈrᵻstᵻs/) is a multi-user time-sharing operating system, initially developed by Evans, Griffiths, & Hart of Boston, and acquired by Digital Equipment Corporation (DEC, now part of Hewlett Packard) for the PDP-11 series of 16-bit minicomputers. The first version of RSTS (RSTS-11, Version 1) was implemented in 1970 by DEC software engineers that developed the TSS-8 time-sharing operating system for the PDP-8. The last version of RSTS (RSTS/E, Version 10.1) was released in September 1992. RSTS-11 and RSTS/E are usually referred to just as "RSTS" and this article will generally use the shorter form.
RSTS can refer to: