TSR

TSR

1. Terminate Stay Resident. A program that is loaded into memory and remain resident in memory allowing the program to function while some other program is operating in the foreground. They are known as "Terminate Stay Resident" because the program returns back the caller (so can be said to have terminated) but "stays resident" in memory. TSR programs were popular in an MS-DOS environment, but are all but obsolete following the arrival of Windows.

2. Terminate Stay Ready. Same as Terminate Stay Resident, but a less common definition.