Permissive licenses are the bread and butter of software development: simple, effective, and on just about everyone’s “go” list. But most information about free and open source software focuses on other, more complex licenses. The Council publishes this list to identify permissive licenses, so that everyone can recognize, rely on, and use them without expensive legal help.
License List
Version 15
This list is also available as JSON and an npm package.
Only the licenses rated Gold, Silver, Bronze, and Lead on this list are Blue Oak certified. You can read more about how licenses are rated below.
You can fund review of more licenses for this list!
Skip To: Model Gold Silver Bronze Lead
Model
The model license demonstrates all the characteristics the council looks for in a permissive open software license.
-
Blue Oak Model License 1.0.0 (
BlueOak-1.0.0
)
Gold
These licenses address patents explicitly, use robust language, and require only simple notice of license terms and copyright notices.
-
BSD-2-Clause Plus Patent License (
BSD-2-Clause-Patent
)
Silver
These licenses use robust language but either fail to address patents explicitly or require more than simple notice of license terms and copyright notices.
-
Apache License 2.0 (
Apache-2.0
) -
Adobe Postscript AFM License (
APAFML
) -
BSD 1-Clause License (
BSD-1-Clause
) -
BSD 2-Clause "Simplified" License (
BSD-2-Clause
) -
BSD 2-Clause FreeBSD License (
BSD-2-Clause-FreeBSD
) -
BSD 2-Clause NetBSD License (
BSD-2-Clause-NetBSD
) -
BSD 2-Clause with Views Sentence (
BSD-2-Clause-Views
) -
Boost Software License 1.0 (
BSL-1.0
) -
DSDP License (
DSDP
) -
Educational Community License v1.0 (
ECL-1.0
) -
Educational Community License v2.0 (
ECL-2.0
) -
hdparm License (
hdparm
) -
ImageMagick License (
ImageMagick
) -
Intel ACPI Software License Agreement (
Intel-ACPI
) -
ISC License (
ISC
) -
Linux Kernel Variant of OpenIB.org license (
Linux-OpenIB
) -
MIT License (
MIT
) -
MIT License Modern Variant (
MIT-Modern-Variant
) -
MIT testregex Variant (
MIT-testregex
) -
MIT Tom Wu Variant (
MIT-Wu
) -
Microsoft Public License (
MS-PL
) -
Mulan Permissive Software License, Version 1 (
MulanPSL-1.0
) -
Mup License (
Mup
) -
PostgreSQL License (
PostgreSQL
) -
Solderpad Hardware License v0.5 (
SHL-0.5
) -
Spencer License 99 (
Spencer-99
) -
Universal Permissive License v1.0 (
UPL-1.0
) -
Xerox License (
Xerox
) -
Xfig License (
Xfig
)
Bronze
These licenses lack important but nonessential elements of permissive open software licenses or impose additional requirements or restrictions, such as BSD-style prohibitions against endorsement and promotion.
-
BSD Zero Clause License (
0BSD
) -
Academic Free License v1.1 (
AFL-1.1
) -
Academic Free License v1.2 (
AFL-1.2
) -
Academic Free License v2.0 (
AFL-2.0
) -
Academic Free License v2.1 (
AFL-2.1
) -
Academic Free License v3.0 (
AFL-3.0
) -
AMD's plpa_map.c License (
AMDPLPA
) -
Apple MIT License (
AML
) -
ANTLR Software Rights Notice (
ANTLR-PD
) -
ANTLR Software Rights Notice with license fallback (
ANTLR-PD-fallback
) -
Apache License 1.0 (
Apache-1.0
) -
Apache License 1.1 (
Apache-1.1
) -
Artistic License 2.0 (
Artistic-2.0
) -
Bahyph License (
Bahyph
) -
Barr License (
Barr
) -
bcrypt Solar Designer License (
bcrypt-Solar-Designer
) -
BSD 3-Clause "New" or "Revised" License (
BSD-3-Clause
) -
BSD with attribution (
BSD-3-Clause-Attribution
) -
BSD 3-Clause Clear License (
BSD-3-Clause-Clear
) -
Hewlett-Packard BSD variant license (
BSD-3-Clause-HP
) -
Lawrence Berkeley National Labs BSD variant license (
BSD-3-Clause-LBNL
) -
BSD 3-Clause Modification (
BSD-3-Clause-Modification
) -
BSD 3-Clause No Nuclear License 2014 (
BSD-3-Clause-No-Nuclear-License-2014
) -
BSD 3-Clause No Nuclear Warranty (
BSD-3-Clause-No-Nuclear-Warranty
) -
BSD 3-Clause Open MPI Variant (
BSD-3-Clause-Open-MPI
) -
BSD 3-Clause Sun Microsystems (
BSD-3-Clause-Sun
) -
BSD 4-Clause "Original" or "Old" License (
BSD-4-Clause
) -
BSD 4-Clause Shortened (
BSD-4-Clause-Shortened
) -
BSD-4-Clause (University of California-Specific) (
BSD-4-Clause-UC
) -
BSD Source Code Attribution (
BSD-Source-Code
) -
bzip2 and libbzip2 License v1.0.5 (
bzip2-1.0.5
) -
bzip2 and libbzip2 License v1.0.6 (
bzip2-1.0.6
) -
Creative Commons Zero v1.0 Universal (
CC0-1.0
) -
CFITSIO License (
CFITSIO
) -
Clips License (
Clips
) -
CNRI Jython License (
CNRI-Jython
) -
CNRI Python License (
CNRI-Python
) -
CNRI Python Open Source GPL Compatible License Agreement (
CNRI-Python-GPL-Compatible
) -
Cube License (
Cube
) -
curl License (
curl
) -
eGenix.com Public License 1.1.0 (
eGenix
) -
Entessa Public License v1.0 (
Entessa
) -
Freetype Project License (
FTL
) -
fwlw License (
fwlw
) -
Historical Permission Notice and Disclaimer - Fenneberg-Livingston variant (
HPND-Fenneberg-Livingston
) -
Historical Permission Notice and Disclaimer - sell regexpr variant (
HPND-sell-regexpr
) -
HTML Tidy License (
HTMLTIDY
) -
IBM PowerPC Initialization and Boot Software (
IBM-pibs
) -
ICU License (
ICU
) -
Info-ZIP License (
Info-ZIP
) -
Intel Open Source License (
Intel
) -
JasPer License (
JasPer-2.0
) -
libpng License (
Libpng
) -
PNG Reference Library version 2 (
libpng-2.0
) -
libtiff License (
libtiff
) -
LaTeX Project Public License v1.3c (
LPPL-1.3c
) -
LZMA SDK License (versions 9.22 and beyond) (
LZMA-SDK-9.22
) -
MIT No Attribution (
MIT-0
) -
Enlightenment License (e16) (
MIT-advertising
) -
CMU License (
MIT-CMU
) -
enna License (
MIT-enna
) -
feh License (
MIT-feh
) -
MIT Open Group Variant (
MIT-open-group
) -
MIT +no-false-attribs license (
MITNFA
) -
Mulan Permissive Software License, Version 2 (
MulanPSL-2.0
) -
Multics License (
Multics
) -
Naumen Public License (
Naumen
) -
Net-SNMP License (
Net-SNMP
) -
NetCDF license (
NetCDF
) -
NICTA Public Software License, Version 1.0 (
NICTA-1.0
) -
NIST Software License (
NIST-Software
) -
NTP License (
NTP
) -
Open Government Licence - Canada (
OGL-Canada-2.0
) -
Open LDAP Public License v2.0 (or possibly 2.0A and 2.0B) (
OLDAP-2.0
) -
Open LDAP Public License v2.0.1 (
OLDAP-2.0.1
) -
Open LDAP Public License v2.1 (
OLDAP-2.1
) -
Open LDAP Public License v2.2 (
OLDAP-2.2
) -
Open LDAP Public License v2.2.1 (
OLDAP-2.2.1
) -
Open LDAP Public License 2.2.2 (
OLDAP-2.2.2
) -
Open LDAP Public License v2.3 (
OLDAP-2.3
) -
Open LDAP Public License v2.4 (
OLDAP-2.4
) -
Open LDAP Public License v2.5 (
OLDAP-2.5
) -
Open LDAP Public License v2.6 (
OLDAP-2.6
) -
Open LDAP Public License v2.7 (
OLDAP-2.7
) -
Open LDAP Public License v2.8 (
OLDAP-2.8
) -
Open Market License (
OML
) -
OpenSSL License (
OpenSSL
) -
PHP License v3.0 (
PHP-3.0
) -
PHP License v3.01 (
PHP-3.01
) -
Plexus Classworlds License (
Plexus
) -
Python Software Foundation License 2.0 (
PSF-2.0
) -
Python License 2.0 (
Python-2.0
) -
Ruby License (
Ruby
) -
Saxpath License (
Saxpath
) -
SGI Free Software License B v2.0 (
SGI-B-2.0
) -
SunPro License (
SunPro
) -
Scheme Widget Library (SWL) Software License Agreement (
SWL
) -
Symlinks License (
Symlinks
) -
TCL/TK License (
TCL
) -
TCP Wrappers License (
TCP-wrappers
) -
UCAR License (
UCAR
) -
Unicode License Agreement - Data Files and Software (2015) (
Unicode-DFS-2015
) -
Unicode License Agreement - Data Files and Software (2016) (
Unicode-DFS-2016
) -
UnixCrypt License (
UnixCrypt
) -
The Unlicense (
Unlicense
) -
Vovida Software License v1.0 (
VSL-1.0
) -
X11 License (
X11
) -
XFree86 License 1.1 (
XFree86-1.1
) -
xlock License (
xlock
) -
X.Net License (
Xnet
) -
XPP License (
xpp
) -
zlib License (
Zlib
) -
zlib/libpng License with Acknowledgement (
zlib-acknowledgement
) -
Zope Public License 2.0 (
ZPL-2.0
) -
Zope Public License 2.1 (
ZPL-2.1
)
Lead
These licenses lack one or more essential elements of permissive open software licenses or impose unusually burdensome requirements. Many use unclear, jocular, or incomplete language.
-
Adobe Systems Incorporated Source Code License Agreement (
Adobe-2006
) -
Afmparse License (
Afmparse
) -
Artistic License 1.0 (
Artistic-1.0
) -
Artistic License 1.0 w/clause 8 (
Artistic-1.0-cl8
) -
Artistic License 1.0 (Perl) (
Artistic-1.0-Perl
) -
Beerware License (
Beerware
) -
SQLite Blessing (
blessing
) -
Borceux license (
Borceux
) -
BSD 2-Clause - Ian Darwin variant (
BSD-2-Clause-Darwin
) -
CeCILL-B Free Software License Agreement (
CECILL-B
) -
check-cvs License (
check-cvs
) -
Clarified Artistic License (
ClArtistic
) -
Condor Public License v1.1 (
Condor-1.1
) -
Crossword License (
Crossword
) -
CrystalStacker License (
CrystalStacker
) -
diffmark license (
diffmark
) -
DOC License (
DOC
) -
Eiffel Forum License v1.0 (
EFL-1.0
) -
Eiffel Forum License v2.0 (
EFL-2.0
) -
Fair License (
Fair
) -
FSF All Permissive License (
FSFAP
) -
FSF Unlimited License (
FSFUL
) -
Giftware License (
Giftware
) -
Good Luck With That Public License (
GLWTPL
) -
HPND with US Government export control warning (
HPND-export-US
) -
Independent JPEG Group License - short (
IJG-short
) -
Jam License (
Jam
) -
Kazlib License (
Kazlib
) -
Leptonica License (
Leptonica
) -
Lucent Public License Version 1.0 (
LPL-1.0
) -
Lucent Public License v1.02 (
LPL-1.02
) -
McPhee Slideshow License (
McPhee-slideshow
) -
MirOS License (
MirOS
) -
mpich2 License (
mpich2
) -
Nara Institute of Science and Technology License (2003) (
NAIST-2003
) -
NASA Open Source Agreement 1.3 (
NASA-1.3
) -
Net Boolean Public License v1 (
NBPL-1.0
) -
Newsletr License (
Newsletr
) -
No Limit Public License (
NLPL
) -
NRL License (
NRL
) -
NTP No Attribution (
NTP-0
) -
OFFIS License (
OFFIS
) -
Open Group Test Suite License (
OGTSL
) -
Open LDAP Public License v1.1 (
OLDAP-1.1
) -
Open LDAP Public License v1.2 (
OLDAP-1.2
) -
Open LDAP Public License v1.3 (
OLDAP-1.3
) -
Open LDAP Public License v1.4 (
OLDAP-1.4
) -
psutils License (
psutils
) -
Python ldap License (
python-ldap
) -
Qhull License (
Qhull
) -
Rdisc License (
Rdisc
) -
RSA Message-Digest License (
RSA-MD
) -
snprintf License (
snprintf
) -
Spencer License 86 (
Spencer-86
) -
Spencer License 94 (
Spencer-94
) -
SSH short notice (
SSH-short
) -
Technische Universitaet Berlin License 1.0 (
TU-Berlin-1.0
) -
Technische Universitaet Berlin License 2.0 (
TU-Berlin-2.0
) -
Vim License (
Vim
) -
W3C Software Notice and License (1998-07-20) (
W3C-19980720
) -
W3C Software Notice and Document License (2015-05-13) (
W3C-20150513
) -
Wsuipa License (
Wsuipa
) -
xinetd License (
xinetd
) -
XSkat License (
XSkat
) -
Zed License (
Zed
) -
Zend License v2.0 (
Zend-2.0
) -
Zope Public License 1.1 (
ZPL-1.1
)
About Our Ratings
Members of Blue Oak Council rate licenses on this list according to their collective judgments of permissiveness and legal rigor, based on their legal knowledge and experience advising clients. They focus on the interest of users and distributors, rather than open software creators or broader policy concerns.
The goal is to create a list that can be incorporated by reference into policies for use use open software by organizations large and small. Most organizations will be comfortable accepting software under any license rated Bronze or better. More conservative organizations can require higher-rated licenses.