| Title | Language | Implementation license | Additional information |
|---|
| GNAT | Ada | GPLv3 | FSF GNAT is GPLv3 with runtime exception, other versions have a GPL runtime. |
| ALGOL 68G |ALGOL 68 |GPL |
| ELLA ALGOL 68 |ALGOL 68 |Public domain or Crown copyright |
| BWK awk | AWK | Custom |
| gawk | AWK | GPLv3 |
| mawk | AWK | GPLv2 |
| GCC |C, C++, Objective-C, ASM, Go |GPL |
| Clang, LLVM |C, C++, Objective-C |NCSA |
| OpenCOBOL |COBOL |GPL |
| Mono |C#, Visual Basic .NET |GPLv2, MIT (X11), LGPLv2 |
| Erlang |Erlang |Erlang, Apache 2.0 |
| Gforth | Forth | GPLv3 |
| Open Firmware | Forth | BSD |
| Pforth | Forth | Public domain |
| FreeBASIC | BASIC | GPL | Inspired by and compatible with QBasic. |
| Gambas | BASIC | GPL | Partially compatible with Visual Basic code. |
| Harbour |Harbour |GPL |
| Helium |Haskell |GPL |
| Icon | Icon | Public domain |
| IcedTea |Java |GPL |
| WebKit JavaScriptCore |JavaScript |LGPL v2.1 |
| SpiderMonkey |JavaScript |MPL |
| V8 |JavaScript |BSD |
| Julia |Julia | MIT, GPL and BSD |A few (optional) GPL math libraries make the full environment GPL as a whole. |
| Emacs Lisp | Lisp | GPLv3 |
| EGL |EGL |EPL |
| Lua |Lua |MIT |
| Logtalk |Logtalk | GPLv3 | linking exception |
| Free Pascal |Pascal, Object Pascal |GPL, LGPL | GPL applies to the compiler, while LGPL with static linking exception applies to the runtime libraries |
| Perl |Perl |Artistic or GPL |
| PHP |PHP |PHP (BSD-style) |
| Pike |Pike |GPL, LGPL, MPL 1.1 |
| Free Poplog | POP-11, Common Lisp, Prolog, Standard ML | Custom, based on MIT/XFree86 |
| GNU Prolog | Prolog | GPLv2 |
| SWI-Prolog | Prolog | LGPL |
| Ciao | Prolog | GPL, LGPL |
| Opa | Opa | Affero GPL |
| Python |Python |PSF (GPL compatible) |With Run-Time Exception (no Copyleft) |
| Jython |Python |PSF (GPL compatible) |With Run-Time Exception (no Copyleft) |
| IronPython |Python |Ms-PL |
| PyPy |Python |MIT |
| Regina | REXX | LGPL |
| Ruby MRI |Ruby |Ruby or GPL | Reference implementation through v1.8 |
| YARV |Ruby |Ruby or BSD | Reference implementation for v1.9; GPL for v1.9.1–1.9.2; BSDL for 1.9.3+ |
| JRuby |Ruby |CPL, GPL, LGPL |
| IronRuby |Ruby |Ms-PL |
| Rubinius |Ruby |BSD |
| XRuby |Ruby |GPL v2 |
| Bigloo |Scheme |GPL, LGPL |
| Chicken |Scheme |BSD |
| Gambit |Scheme |LGPL, Apache |
| Guile | Scheme | LGPL |
| JScheme |Scheme |zlib |
| BiwaScheme |Scheme |MIT |
| Kawa |Scheme |MIT |
| Racket | Scheme | LGPL |
| Scsh | Scheme | BSD |
| GNU Smalltalk |Smalltalk |GPL v2 |
| Pharo |Smalltalk |MIT |
| Squeak |Smalltalk |Apple Public Source, Apache (OLTPC) |
| CSNOBOL4 | SNOBOL4 | Custom |
| Tcl/Tk | Tcl/Tk | Tcl/Tk (BSD-style) |
| MINT | TRAC | GPL |
| ash | Unix Shell | BSD |
| bash | Unix Shell | GPLv3 |
| ksh93 | Unix Shell | CPL |
| Clojure | Clojure | EPL |
| ClojureCLR | Clojure | EPL |
| Clojure-Py | Clojure | EPL |
| ClojureScript | Clojure | EPL |
| Scala | Scala | BSD |
| F# | F# | MIT |
| TypeScript | TypeScript | Apache |
| Go | Go | BSD-style |
| Rust | Rust | MIT |
| Vala | Vala | LGPL |
| Dart | Dart | BSD |
| Multics PL/I | PL/I | MIT |
| R | R | GPL |
| Swift | Swift | Apache |
| .NET Core | C#, Visual Basic .NET, F# | MIT |
| Nim | Nim | MIT |
| Crystal | Crystal | Apache |
|
{{DEFAULTSORT:Open-source programming languages}}