RSX-11
| Developer | Digital Equipment Corporation | 
|---|---|
| Written in | MACRO-11, BLISS | 
| Working state | Discontinued | 
| Source model | Closed source; kernel source code included | 
| Initial release | 1972 | 
| Latest release | RSX-11M Plus 4.6 / 1999 | 
| Platforms | PDP-11 | 
| Influenced | OpenVMS | 
| Influenced by | RSX-15 | 
| Default user interface | DCL and MCR Command-line interface | 
| License | Proprietary | 
RSX-11 is a discontinued family of multi-user real-time operating systems for PDP-11 computers created by Digital Equipment Corporation. In widespread use through the late 1970s and early 1980s, RSX-11 was influential in the development of later operating systems such as VMS and Windows NT.
As the original Real-Time System Executive name suggests, RSX was designed (and commonly used) for real time use, with process control a major use. It was also popular for program development and general computing.