| Algol H | ⊕ 1975 | ↓ ↑ ⊕ Experimental and other | ⊕ True ALGOL68s | ⊕ United Kingdom | Proposed extensions to the mode system of Algol 68 |
| CABALA | ⊕ 1975 | ↓ ↑ ⊕ Experimental and other | ⊕ Scientific Basics | ⊕ Italy | Extensions to Basic for laboratory work |
| GRAP | ⊕ 1975 | ↓ ↑ ⊕ Experimental and other | ⊕ United States | ||
| Greif formal specification language | ⊕ 1975 | ↓ ↑ ⊕ Experimental and other | ⊕ United States | ||
| LUCID | ⊕ 1975 | ↓ ↑ ⊕ Experimental and other | ⊕ Single-assignment | ⊕ Canada | dataflow language |