Comparison of open-source programming language licensing
This is a comparison of open-source programming language licensing and related legal issues, covering all language implementations. Open-source programming languages are those that are released under open-source licenses.
| 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, LGPLv2 | - |
| ' | Eiffel | GPL, EFL | For GPL projects |
| ' | Eiffel | MIT | - |
| 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 GPL math libraries make the full environment GPL as a whole. |
| Emacs Lisp | Lisp | GPLv3 | - |
| EGL | EGL | EPL | - |
| Lua | Lua | MIT | - |
| Logtalk | Logtalk | Apache 2.0 | 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 | - |
| 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 | With Run-Time Exception |
| Jython | Python | PSF | With Run-Time Exception |
| 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 | - |
| CSNOBOL4 | SNOBOL4 | Custom | - |
| Tcl/Tk | Tcl/Tk | Tcl/Tk | - |
| 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 | - |