Tenberry Software
| Formerly | Rational Systems |
|---|---|
| Type | Private |
| Industry | Software, DOS extenders |
| Headquarters | Phoenix, Arizona, United States |
| Key people | Terence Colligan (president) |
| Products | DOS/16M, DOS/4G, DOS/4GW |
Tenberry Software, formerly Rational Systems, was a software company based in Phoenix, Arizona, best known for developing DOS/4G and DOS/4GW, DOS extenders that became a de facto standard for running 32-bit software under 16-bit MS-DOS in the early 1990s. The company also developed DOS/16M, an earlier extender that enabled 16-bit applications to access extended memory beyond the conventional 640 KB limit.