SIL Open Font License revised


Author: Bruce Byfield

SIL International, a nonprofit organization whose concerns include literacy and the study and preservation of minority languages, has announced the release of version 1.1 of the SIL Open Font License (OFL). The revision, which follows months of discussion and review on several mailing lists, including OFL-Discuss, clarifies the language of the license, especially about embedding fonts and allowing reserved font names.

The Open Font License was first released in November 2005. Written by Nicolas Spalinger, a SIL volunteer, and Victor Gaultney, a SIL typeface designer, the license is intended to be compatible with free and open source software while addressing the concerns of designers. For instance, in order to prevent resellers taking advantage of a free font, the license prohibits selling a font that uses the license by itself, or in a collection unaccompanied by software. Similarly, in order to preserve the artistic integrity of a typeface, designers can specify reserved font names that creators of derivative works can use only with permission. These provisions are easily circumvented — for example, fonts could be sold with a “Hello, World” script while derivatives could be named with a synonym that points to the original. However, Gaultney states that, without them, designers would be more resistant to the idea of developing free fonts.

SIL has posted a summary of the changes in the revision online. Some of the changes are largely cosmetic, explained in the summary as simply “better wording,” but many are intended to reduce ambiguities and potential problems. For instance, complaints about the definition of “standard” led to the replacement of the word with “original” when referring to the collection of files released by the designer. Similarly, the definition of “font software” no longer specifies the types of files, but covers any files released under the copyright.

Some of the most important clarifications in version 1.1 concern embedding, or the addition of a typeface to a document. Embedding is an option in the creation of PDF files, and also occurs when characters are converted to a graphic in word processing or desktop publishing files. The question of whether licenses permit embedding has come up frequently, and Spalinger and Gaultney wanted to make clear that the OFL permitted it. “This was always the case,” Gaultney says, “but we made it clearer because there was some confusion.” The prohibition against releasing OFL fonts under another license now adds the sentence, “The requirement for fonts to remain under this license does not apply to any document created using the fonts or their derivatives” in order to clarify the status of embedded fonts. In addition, version 1.1 specifies that embedding is not incompatible with selling the font.

The largest group of changes to the license refers to reserved font names. “We take great care to give authors a clear way to reserve font names that only they can use,” Gaultney explains. “This is to keep someone else from releasing a font that could be mistaken for yours. We wanted to make it easier to associate particular reserved font names with particular copyright holders, so the ownership of the names was clear.”

To this end, reserved font names no longer include names “as seen by users” as a file name or in a font list in other software. Instead, reserved font names refer only to those specified in the copyright statement. Similarly, the restriction on derivative works using the reserved font names omits the phrase “in part or in whole” because, as the revision page notes, “it could be interpreted to mean that any font based on ‘Foobar’ could not use the letters f, o, b, a, or r in the font name.” In addition, restrictions on font names “only applies to the primary font name as presented to the users” to eliminate concern over reserved names appearing in the metadata of font files.

Reaction to the new version of the license has been generally positive. Gaultney notes that a number of free typeface designers “have joined together to create an OFL promotion campaign that should be unveiled in a few weeks.” The Open Font Library, a sister project to the Open Clipart Library, is considering using the OFL for all submissions, while George Williams, the lead developer of FontForge, the leading free software for typographical design, has added a button that automatically adds the OFL into the license field of a font file.

Outside the world of designers, Gaultney notes that the Free Software Foundation “confirm that the OFL 1.1 remains a free license, just like 1.0.” The largest remaining resistance to the license comes from the debian-legal mailing list, where a few posters continue to argue that the OFL is not compatible with the Debian Free Software Guidelines, which defines what is acceptable for inclusion in Debian’s main archives. However, as Gaultney points out, this opinion seems a minority one, since several OFL fonts, including his own Gentium, have already been included in Debian’s main archives by the FTP site managers.

No one knows the exact number of fonts released under the OFL, but Gaultney says that “there are at least 20 fonts that I know about, and many others I don’t.”

Whether the OFL created the free font movement that has become prominent in the last year or simply reflects its growth is uncertain, but in little more than a year, the license seems to have become an accepted part of its community.

Bruce Byfield is a computer journalist who writes regularly for NewsForge,, and IT Manager’s Journal.


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