Typeface

Memo on some of the best free typefaces.

Sans-serif

Nimbus Sans L

GPL, AFPL, and LPPL.

The typeface of choice if there needs to be a single typeface for everything. It serves the most fundamental purpose of text - conveying written message - most correctly and clearly. It doesn’t have any “look” or “expression” at all, attaching absolutely no atmosphere to the pure content.

Helvetica is known better for having completely neutral expression, but it’s not free (important). Surprisingly, the Nimbus Sans family predates Helvetica.

Arimo

Apache License 2.0.

High on-screen readability. The single most recommendable web typeface for most websites. Not as tasteless and scentless as Nimbus Sans L, but still objective enough to fit under all circumstances. Compared to the flatness of Nimbus Sans L that rejects emotion, Arimo has a hint of modernistic positiveness and looks relatively “newer.”

If you take Arimo’s sentiment further you get Open Sans.

Roboto

Apache License 2.0.

The default typeface of Android. Its slightly futuristic and electronic feeling comes from that some elements, compared to more traditional sans-serif ones, are reduced to a simpler geometric form, possibly to enhance readability in a multitude of screen resolution.

Open Sans

Apache License 2.0.

Contrary to Roboto, Open Sans leans to “modern” instead of “future.” It’s cool and organized well enough to deserve the name “Open Sans”, but is not at all a dead pan like Nimbus Sans L, manifesting optimism. A nice flavor of curvy elegance is added which is both friendly and professional. Take this sentiment further and you get Lato.

A beauitful example of web design centered around Open Sans is Mozilla’s Sandstone.

Lato

Open Font License.

Lato is a very successful attempt to design a modern alternative typeface for modern websites in 2010. As its name (meaning “summer” in Polish) suggests, it definitely has a cheerful quality, but this never goes too far to harm legibility or break coherence. The hidden innocent mischief is in lowercase ‘e’ whose central horizontal line is positioned above the ordinary placement.

Lato looks like what Tahoma and Verdana wished (and failed) to do. Web apps and services are highly encouraged to choose Lato, just as the web-based IRC client Shout’s default theme did.

Monospace

Envy Code R

Someone really should raise fund to construct a fleet of gigantic balloons with hanging placards that will float in Redmond, Washington to urge Damien to release the official Envy Code R 1.0.