| *Lisp | 1985 | parallel computing | dynamic typing | — |
| Lasso | 1995 | concurrent computing, procedural programming, structured programming, object-oriented programming | dynamic typing, nominative typing, duck typing | — |
| LC-3 | — | — | — | — |
| Le Lisp | 1981 | — | — | — |
| Lean | 2013 | functional programming | — | 1 |
| Lean 3 file format | — | — | — | — |
| Lean 4 file format | — | — | — | — |
| Leet | — | — | — | — |
| LFE | 2008 | functional programming | dynamic typing, strong typing | — |
| Liberty BASIC | 1992 | event-driven programming | dynamic typing | — |
| LibreOffice Basic | — | — | — | — |
| Light.vn | 2024 | — | — | — |
| Limbo | 1995 | concurrent computing, modular programming | strong typing | 2 |
| Linda | 1985 | — | — | — |
| Linden Scripting Language | — | — | — | — |
| Lingo | 1989 | object-oriented programming | — | — |
| Links | 2006 | — | — | — |
| Linotte | 2005 | object-oriented programming | — | — |
| Lioness | — | — | dynamic typing | — |
| LIPS | 2018 | — | — | — |
| Liquidsoap | — | — | — | — |
| Lisaac | 2003 | object-oriented programming | — | — |
| Lisp | 1958 | reflective programming, procedural programming, functional programming, multi-paradigm programming, metaprogramming | dynamic typing, strong typing | 39 |
| Lisp Machine Lisp | 1976 | object-oriented programming | — | 1 |
| Lisp-based Intelligent Software Agents | — | — | — | — |
| LispWorks | — | — | dynamic typing | — |
| Little b | 2004 | functional programming, object-oriented programming | dynamic typing, strong typing | — |
| Little Smalltalk | — | — | — | — |
| LiveCode | 2001 | object-oriented programming | — | — |
| LiveScript | 2011 | functional programming, object-oriented programming | dynamic typing, weak typing | 1 |
| LiveScript | — | — | — | — |
| Locomotive BASIC | 1984 | — | — | — |
| Lodu Code | — | — | — | — |
| Logica | — | — | — | — |
| Logo | 1967 | reflective programming, procedural programming, functional programming | dynamic typing | 11 |
| Logtalk | 1998 | prototype-based programming, logic programming, object-oriented programming | — | — |
| LOLCODE | 2007 | procedural programming, structured programming, imperative programming | — | — |
| LPC | 1989 | procedural programming, prototype-based programming, functional programming, object-oriented programming | dynamic typing, static typing, weak typing, strong typing | 1 |
| LSE | 1960 | procedural programming, structured programming | — | — |
| Lua | 1993 | procedural programming, prototype-based programming, functional programming, imperative programming, multi-paradigm programming, object-oriented programming | dynamic typing, duck typing, strong typing | 9 |
| Luau | — | — | — | — |
| Lucee | 2015 | — | dynamic typing | — |
| Lucid | 1976 | dataflow programming, concurrent computing, reactive programming, declarative programming | — | — |
| Luna | 2011 | — | — | — |
| Lustre | 1980 | dataflow programming, synchronous programming, declarative programming | — | — |
| LYaPAS | 1964 | functional programming, structured programming, array programming, modular programming | dynamic typing | — |
| Lynx | 1984 | — | — | — |