More Seven Theme issues:
Short version: The style guide for the updated default Seven admin theme proposes to use the Source Sanse Pro font. Source Sans Pro is not only free but open source, available under the SIL Open Font License (OFL). We propose to include a webfont version of Source Sans Pro be included with the Seven theme.
- Figure out if we can, license-wise
- Decide if we will (our rationale below)
- If so, do it
Rationale for the use of Source Sanse Pro
This guide proposes all text be set in Source Sans Pro from Adobe. Similar in character to Lucida Sans (the existing typeface specified by Seven), Source Sans is a professionally designed, fully open-source type family that falls into the general category of “humanist sans-serif”. Fonts of this type combine the modern geometric and industrial-age characteristics of sans-serif typefaces with the calligraphic and handwritten qualities of Renaissance letterforms. This balance of the engineered and the human matches well with the Drupal brand.
Seven’s original choice of Lucida was a good one for those same reasons, but also for a very practical one: legibility in UI. Source Sans is arguably even better in this respect, with glyphs such as lowercase L and upper/lower I all easily distinguishable from one another, even at small sizes. This is one of many details to consider when choosing a typeface for UI work, and where some common choices – like Helvetica – fare poorly.
Source sans also provides a versatile set of weights, including a semibold.
Source Sans is one of the few professionally-designed typefaces that is not only free but open source, available under the SIL Open Font License (OFL). However, it is unclear whether the OFL would allow it to be included as part of Drupal core. The Wikipedia page on OFL states that it is not GPL-compatible. However, SIL’s own FAQ states, under a question about bundling with GNU/Linux that “Fonts licensed under the OFL can be freely included alongside other software under FLOSS (Free/Libre and Open Source Software) licenses. Since fonts are typically aggregated with, not merged into, existing software, there is little need to be concerned about incompatibility with existing software licenses.”
Provided the OFL license is compatible and the community supports it, this guide proposes that a webfont version of Source Sans Pro be included with the Seven theme. To keep file size and HTTP requests down as well as to simplify the design system, not all of the fonts that make up the complete type family would need to be included. This guide uses the Regular, Italic, Semibold and Bold fonts.
So to repeat the main points:
1. Figure out if we can include the font files in the Drupal project, license-wise
2. Decide if we will
3. If so, do it!
4. If not, figure out if we can find a way to download the files from an external server without harming UX.