| PLAN | 1968 | Specialised Languages | Plan languages | United States | |
| PLAN | 1998 | network programminglanguage | |||
| PLAN | 1965 | Symbolic assemblers | United States | ICL Symbolic assembler | |
| PLAN2D | 1976 | ||||
| PLANCODE | 1976 | ||||
| Plane Lucid | 1988 | Business Data Processing | 3D Spreadsheets | United States | 3d spreadsheet language |
| Planet | 1984 | ||||
| PLANIT | 1967 | Specialised Languages | CAI languages | United States | Umich/SDC CAI language |
| Plankalkul | 1943 | Excluded from Sammet | W European algorithmic systems | Germany | Algebraic compiler for Z3 |
| PLANNER | 1967 | String and List Processing | Goal description | United States | Goal-direct LISP dialect |
| PLANNER-73 | 1973 | United States | |||
| PLANS | 1977 | United States |