NRSI: Computers & Writing Systems
SIL Open Font License (OFL)
Draft OFL-FAQ update available for review
There is a draft of an OFL-FAQ update (version 1.1-update3-draft) available for review and comment. The main changes are related to web font use and modification. There is also a separate discussion paper on Web Font and Reserved Font Names. We welcome your comments on both documents.
The SIL Open Font License (OFL) is a free, libre and open source license specifically designed for fonts and related software based on our experience in font design and linguistic software engineering.
The OFL provides a legal framework and infrastructure for worldwide development, sharing and improvement of fonts and related software in a collaborative manner. It enables font authors to release their work under a common license that allows use, bundling, modification and redistribution. It encourages shared value, is not limited to any specific computing platform or environment, and can be used by other organizations or individuals.
The OFL meets the specific needs of typographic design and engineering as well as the gold standards of the FLOSS (Free/Libre and Open Source Software) community, namely the cultural values and guidelines from the FSF 1, the Debian Free Software Guidelines2, as well as the Open Source Definition3. It draws inspiration from concepts and elements found in other licenses, but our improvements in the specific area of fonts have made the licensing model work better than other approaches currently in use.
SIL International serves language communities worldwide, building their capacity for sustainable language development, by means of research, translation, training and materials development. We have been thinking about more open and participative models for a while, for example through our partnerships with UNESCO (Initiative B@bel) and our work on the Gentium typeface.
We want to:
We serve the peoples of the world without regard to their material wealth, so we are grateful to those that do fund our work. Please visit Donate to SIL International for information on supporting our efforts.
We have gone through a lot of effort to make our license readable and easily understood by users, designers and software developers as well as package maintainers and distributors. To make the OFL even more human-readable, we have provided a FAQ (Frequently Asked Questions) to help everyone understand the intent and the practical aspects of using the license itself. Although it already covers many items, the FAQ will grow as needed. Please let us know if you have more questions.
Current version - 1.1
We recommend all authors use version 1.1 of the OFL, but version 1.0 is given here for reference. A full list of changes from 1.0 to 1.1 can be found on the OFL Review page. The most important change for authors is that no font names are reserved by default. Reserved Font Names must be explicitly listed alongside the copyright statement in the OFL header.
OFL 1.1 Documents
OFL 1.0 Documents (for reference only)
We also recognise the need for people who are not familiar with English to be able to understand the OFL and this FAQ better - in their own language. If you are an experienced translator, you are very welcome to help by translating the OFL and its FAQ so that designers and users in your language community can understand the license better. But only the original English version of the license has legal value and has been approved by the community. Translations do not count as legal substitutes and should only serve as a way to explain the original license. SIL - as the author and steward of the license for the community at large - does not approve any translation of the OFL as legally valid because even small translation ambiguities could be abused and create problems.
We give permission to publish unofficial translations into other languages provided that they comply with the following guidelines:
1) Put the following disclaimer in both English and the target language stating clearly that the translation is unofficial:
"This is an unofficial translation of the SIL Open Font License into $language. It was not published by SIL International, and does not legally state the distribution terms for fonts that use the OFL. A release under the OFL is only valid when using the original English text.
However, we recognize that this unofficial translation will help users and designers
not familiar with English to understand the SIL OFL better and make it easier to use and release font
families under this collaborative font design model. We encourage designers who consider releasing their
creation under the OFL to read the FAQ in their own language if it is available.
2) Keep your unofficial translation current and update it at our request if needed, for example, if there is any ambiguity which could lead to confusion.
If you start such a unofficial translation effort of the OFL and its accompanying FAQ please let us know, thank you.
Using the OFL
It is relatively simple to use the OFL for your own font project. If you are the copyright owner you only need to do the following:
More information can be found in the OFL-FAQ.
Current version: 1.1
2010-08-23 - OFL-FAQ 1.1-update2.
2009-04-06 - OFL recognized as compliant with the OSD (Open Source Definition) by the OSI board and placed on their list of approved licenses.
2007-02-26 - Version 1.1 released.
2006-03-18 - A minor revision of the OFL entered the review phase. OFL-1.1-review1 was followed by OFL-1.1-review2 a few months later.
2006-01-23 - OFL recognized as a free license by the FSF (Free Software Foundation) on their License List.
2005-11-22 - Version 1.0 released.
2005-11-07 - Version 1.0-review2 submitted to ofl-discuss.
2005-09-07 - Version 1.0-review1 submitted to the first round of public reviewers.
Between November 2005 and January 2007 the OFL was in a public review stage, with efforts going towards version 1.1. We selected a number of reviewers we felt were the relevant experts and sought their input. We submitted our draft for review and received very insightful feedback.
The review period is over and even though we feel version 1.1 will likely meet the needs for open font licensing for quite some time, we remain open to community feedback. Please contact us with your queries and suggestions.
Various font-related BoFs (Birds of a Feather meetings) have taken place at recent FLOSS conference (like Libre Graphics Meeting, Ubuntu Summit, GUADEC, DebConf, TextLayoutSummit among others) to discuss what would be needed to improve the font landscape. One key aspect was appropriate licensing of the fonts, flexibility to maintain and branch fonts without breaking rendering, interoperability across distributions, and the definition of a core set of fonts with recognized glyph quality, sufficient Unicode coverage and a good community-recognized license. The OFL has been recognised by many contributors to these discussion as a good solution for these issues.
The goals of the OFL and its methodology have been presented and discussed at major conferences from the type industry like AtypI.
Open font-related presentation have also been made at TUG (TeX User Group conferences.
There is a campaign with support from various key organisations in the FLOSS community (Unifont.org, Freedesktop.org, the GNOME foundation, KDE e.V., the Linux Foundation and the Free Software Foundation) to encourage more designers and supporting institutions to consider choosing the OFL for their font projects. Visit Unifont.org/go_for_ofl for more details and ways you can participate.
The OFL is now well-established as the most widely used licensing model for releasing and developing unrestricted font software. It is being used successfully by various organisations, both for-profit and not-for-profit, to release fonts of varying levels of scope and complexity. A number of institutions have now made the OFL their default recommended license.
We intend to use the OFL for all our future font releases, and will re-release our existing and older font packages under the OFL as we have personnel time. The priority of older packages will depend on demand.
If you release (or intend to release) your font(s) under the OFL, let us know and we may place a link to the fonts on our OFL fonts page.
Details and rationale
The OFL is designed to be in tune with the FLOSS (Free/Libre and Open Source Software) culture. It builds upon good ideas already in existence in some free/libre and open projects but by bringing our extensive font design experience and linguistic software engineering know-how into the mix, we have produced a font-specific license which is simpler, more human-readable, neutral and 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 have also studied the community impact and some of the difficulties faced by this model.
The 4 FSF Freedoms
The OFL is listed and recognized as a valid Free Software license on the FSF License List. It complies with the Free Software Definition and its four foundational freedoms as defined by the Free Software Foundation for the GNU project:
Font Software released under the OFL complies with the Debian Free Software Guidelines:
Various font families under OFL have been accepted in the main archive of Debian (as well as Ubuntu) by the ftp-masters. An increasing number of Debian and Ubuntu developers are maintaining font packages under the OFL in main (the component of the archive which only holds Free/Libre and Open Source software).
The OFL complies with the Open Source Definition:
The OSI (Open Source Initiative) has recognized the OFL's compliance with the OSD and placed it on their list of approved licenses.
"Human readable" version and visual representation
The spirit and working model of the OFL can be expressed in human-readable Creative Commons-like 4 terminology using the following permits / requires elements and visual representations:
Please note that this terminology and visual representation is simply an expression of the working model of the license and has no legal value in itself. It is designed to help you understand and use the Open Font License in a similar way to the OFL FAQ. It is always intended to link back to the full license text of the OFL. Please note that although the terminology and visual representation of the OFL is based on work by Creative Commons, the OFL is not officially affiliated with Creative Commons.
(the Distribution, Reproduction, DerivativeWorks and Notice elements are implied and not represented as icons).
This is what each icon means:
The icon shows a person and represents the author(s).
The icon shows a cycle and represents the way font sofware can be re-used by all under equivalent
The icon shows a letter on a piece of paper and represents a font placed inside a document.
The icon shows letters A and B close to each other representing a font (A) from which another font (B) of
a different shape is derived. It refers to a derivative branched from the original font and bearing a new
The icon shows a dollar sign between parentheses. The dollar sign represents money (although there are
many other currencies in the world) and the parentheses refers to the bundling.
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