The term “open source font”

If you’re looking to customize or contribute to an open source typeface, it’s worth being aware of the ambiguity that can come with the term open source fonts.

When people talk about open source fonts (or open source software more broadly), they often are using it as shorthand for freely licensed and open source software. I find considering those two pieces separately to be helful, when I am evaluating what state an open source font project is in.

Whether you are actually considering contributing to an open source typeface, or considering modifying or integrating something from one as part of a project, or even just going through the source files of one to learn how another type designer works—I think it’s worth considering these two pieces of open source fonts in isolation to have a better understanding what you are evaluating.

This is not even close to a definitive definition of free and open source software or fonts, but more like: some questions you might what to ask yourself when you are considering modifying an open source font.

Freely licensed

The font is licensed in a way where anyone can use it for any purpose, and has access and ability to modify and distribute it.

You’re most likely to encounter the SIL Open Font License, or OFL. The OFL requires that any new work is also distributed under the OFL, which is an incredibly important detail depending on what you are hoping to do.

Open (and ready-to-use) source files

Any typeface that is freely licensed, by definition, should have source files available. In practice, open source fonts can be strange for this because 

Unlike software libraries, where the “source code” is more likely to “the thing” that is open source, that isn’t quite the same for fonts. A .otf file might be distributed under the Open Font License, and while the source files should be “available,” whether or not it’s possibly to reliably reproduce that .otf file is another question entirely.

Say you are looking to customize an existing typeface for a commissioned project, and are expecting to need to extend the language support since most open source typefaces don’t cover a certain glyph you know you’ll need. What is the overhead on adding a single glyph, and exporting a new font file, with all of the production considerations that went into the original font file?

Until next time,