| 2-step | ⊕ 1991 | ⊕ United States | |||
| AIMMS | ⊕ 1991 | ||||
| AKL | ⊕ 1991 | ⊕ Japan | Andorra Kernel Language | ||
| ALJABR | ⊕ 1991 | ⊕ United States | MACSYMA for the Mac | ||
| Bob | ⊕ 1991 | Tiny object-oriented language | |||
| Calico | ⊕ 1991 | ⊕ United States | |||
| cantata | ⊕ 1991 | ⊕ United States | |||
| DataVis | ⊕ 1991 | ⊕ United States | |||
| Delirium | ⊕ 1991 | ⊕ United States | |||
| FORMAN | ⊕ 1991 | ⊕ United States | |||
| Formula | ⊕ 1991 | ⊕ United States | |||
| Glue-Nail | ⊕ 1991 | ⊕ United States | |||
| IRDATA | ⊕ 1991 | ⊕ Germany | |||
| Iris | ⊕ 1991 | ⊕ United States | |||
| Jade | ⊕ 1991 | ⊕ United States | Device independant parallel programming language | ||
| Kid | ⊕ 1991 | ⊕ United States | |||
| KMODEL | ⊕ 1991 | ⊕ Germany | |||
| LIANA | ⊕ 1991 | ⊕ United States | Interpretive c-like language | ||
| MCL | ⊕ 1991 | ⊕ United States | Macintosh Common LISP | ||
| Oberon-2 | ⊕ 1991 | ⊕ Switzerland | |||
| O'Small | ⊕ 1991 | ⊕ United States | |||
| Paragon | ⊕ 1991 | ||||
| PICL | ⊕ 1991 | ⊕ United States | |||
| PROCOL | ⊕ 1991 | ||||
| PROGRES | ⊕ 1991 | ⊕ Germany | |||
| PROSIT | ⊕ 1991 | ⊕ United States | Programming in SItuation Theory | ||
| Python | ⊕ 1991 | ⊕ Netherlands | String based scripting language | ||
| Quintec-Objects | ⊕ 1991 | ⊕ United Kingdom | |||
| SetLog | ⊕ 1991 | ⊕ United States | |||
| Siri | ⊕ 1991 | ⊕ United States | |||
| SNOOPS | ⊕ 1991 | ⊕ United States | |||
| STAR | ⊕ 1991 | ⊕ Russian Federation | |||
| USL | ⊕ 1991 | ⊕ United States | |||
| VCODE | ⊕ 1991 | ⊕ United States | Intermediate language used in the compilation of NESL |