The SIL Open Font License is an approved free, libre and open source license used by a wide variety of individuals and organizations. It has now become the most widely used free, libre, and open source license for fonts. It provides solid benefits for both font users and font creators:

• A proven and widely accepted license and legal framework
• Protects the reputation, authorship, and copyright of font creators: designers and font engineers
• No restrictions on ways the fonts can be used
• Provides a clear process for making legal derivatives
• Actively maintained and supported

Who uses the OFL?

The OFL is used by a wonderfully diverse range of individuals and organizations:

• Font designers from small and large foundries who want to release fonts under a solid, open license framework
• Developers who need special-purpose fonts and don’t have the expertise or time to start a new font project from scratch
• Distributed development teams who want to invite wide participation in their projects
• Experts who need free and open resources for academic research and publishing
• Public administrations, educational institutions and non-profits who wish to use freely available resources
• Web designers who want excellent fonts without depending on expensive commercial webfonts
• Publishers and content developers who want to enable wide, free distribution
• International corporations who value the transparency and control of open systems
• Operating systems developers (Apple, Microsoft, Google, Debian, Ubuntu, etc.) who want to support a wide range of writing systems

Why people choose to use the OFL

People use the OFL for many different purposes and reasons:

• to meet needs for fonts that can be modified to support lesser-known languages
• to provide a legal and clear way for people to respect their work but still use it (and so reduce piracy)
• to involve others in their font project
• to enable their fonts to be expanded with new weights and improved writing system/language support
• to allow more technical font developers to add features to their design (such as OpenType, Graphite or AAT support)
• to renew the life of an old font lying on their hard drive with no business model
• to allow their font to be included in Libre Software operating systems like Ubuntu
• to give their font world status and wide, unrestricted distribution
• to educate students about quality typeface and font design
• to expand their test base and get more useful feedback
• to extend their reach to new markets when users see their metadata and go to their website
• to get their font more easily into one of the webfont online services
• to attract attention for their commercial fonts
• to make money through webfont services
• to make money by bundling fonts with applications
• to make money adjusting and extending existing open fonts
• to get a better chance that foundations, NGOs, charities, or companies who commission fonts will pick them
• to be part of a sharing design and development community
• to give back and contribute to a growing body of font sources

The OFL is an approved free, libre and open source license

The OFL is designed to be in tune with Free/Libre and Open Source Software (FLOSS) culture. It builds upon good ideas already in existence in some free/libre and open projects. It was developed by matching extensive font design experience and linguistic software engineering know-how with established free/libre legal models to produce a font-specific license which is simpler, more human-readable, neutral, reusable, and dedicated to the needs of font creators.

The OFL authors were inspired by the partnership between GNOME and Bitstream for the Vera family of fonts and the licensing model which was chosen. They studied the community impact and some of the difficulties faced by this model. They received insightful feedback from both the type and FLOSS communities to refine a more generic model in order to make it work for everyone.

In compliance with the Free Software Definition

The OFL is listed and recognized by the Free Software Foundation (FSF) as a valid Free Software license. They have added it to their License List. It complies with the Free Software Definition and its four foundational freedoms as defined by the FSF for the GNU project:

• Use: the freedom to use font software for any purpose. (freedom 0)
• Study and adaptation: the freedom to study how font software works, and adapt it to your needs (freedom 1). Access and rights to the source code is a precondition for this.
• Redistribution: the freedom to redistribute copies of the font software so you can help your neighbor (freedom 2).
• Improvement and redistribution of modifications: the freedom to improve the font software and release your improvements (freedom 3), so that the community benefits. Access and rights to the source code is a precondition for this.

In compliance with the Debian Free Software Guidelines

Font Software released under the OFL complies with the DFSG version 1.2 from October 1st, 2022:

1. Free Redistribution
   The license of a Debian component may not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license may not require a royalty or other fee for such sale.
2. Source Code
   The program must include source code, and must allow distribution in source code as well as compiled form.
3. Derived Works
   The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.
4. Integrity of The Author’s Source Code
   The license may restrict source-code from being distributed in modified form only if the license allows the distribution of “patch files” with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software. (This is a compromise. The Debian group encourages all authors not to restrict any files, source or binary, from being modified.)
5. No Discrimination Against Persons or Groups
   The license must not discriminate against any person or group of persons.
6. No Discrimination Against Fields of Endeavor
   The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.
7. Distribution of License
   The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties.
8. License Must Not Be Specific to Debian
   The rights attached to the program must not depend on the program’s being part of a Debian system. If the program is extracted from Debian and used or distributed without Debian but otherwise within the terms of the program’s license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the Debian system.
9. License Must Not Contaminate Other Software
   The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be free software.
10. Example Licenses
    The “GPL”, “BSD”, and “Artistic” licenses are examples of licenses that we consider “free”.

Various font families under the OFL have been accepted in the main archive of Debian as well as Ubuntu by the ftp-masters who decide what gets into the software archives. An increasing number of Debian and Ubuntu developers are maintaining font packages under the OFL in main (the component of the archive which only contains Free/Libre and Open Source software).

In compliance with the Open Source Definition

The OFL complies with the Open Source Definition version 1.9 from March 22nd, 2007:

Introduction
Open source doesn’t just mean access to the source code. The distribution terms of open-source software must comply with the following criteria:

1. Free Redistribution
   The license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.
2. Source Code
   The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of obtaining the source code for no more than a reasonable reproduction cost, preferably downloading via the Internet without charge. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed.
3. Derived Works
   The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.
4. Integrity of The Author’s Source Code
   The license may restrict source-code from being distributed in modified form only if the license allows the distribution of “patch files” with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software.
5. No Discrimination Against Persons or Groups
   The license must not discriminate against any person or group of persons.
6. No Discrimination Against Fields of Endeavor
   The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.
7. Distribution of License
   The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties.
8. License Must Not Be Specific to a Product
   The rights attached to the program must not depend on the program’s being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program’s license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution.
9. License Must Not Restrict Other Software
   The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.
10. License Must Be Technology-Neutral
    No provision of the license may be predicated on any individual technology or style of interface.

The Open Source Initiative (OSI) has recognized the OFL’s compliance with the Open Source Definition and added it to their list of OSI-approved licenses.

The OFL is maintained and supported

The SIL Open Font License was authored and established by SIL International, and continues to be maintained and supported by members of SIL’s WSTech (Writing Systems Technology) team:

• Victor Gaultney - Senior Type Designer and Technical Director (WSTech), SIL International; Associate Lecturer, University of Reading.
• Nicolas Spalinger - Script Engineer, SIL International.

You can be confident that SIL International will continue to act as a responsible steward of the license for the benefit of the community at large.

Last updated on 24 January 2024