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 (X11), LGPLv2
ISE Eiffel	Eiffel	GPL, EFL	For GPL projects (there is a commercial license to use for non GPL projects)
Gobo Eiffel	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 (optional) 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 (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
STklos	Scheme	GPL
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
Zig	Zig	MIT
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