What font does GitHub use? The closest font you can get for the GitHub logo is Collegiate font.…
What font does Zimbra use? The closest font you can get for the Zimbra logo is VAG Rounded Light font.
Developed for Volkswagen AG in 1979, VAG Rounded is a variation on nineteenth-century grotesque sans serif designs
Free alternative fonts for Zimbra logo:
The closest free font you can get is Print Bold Font.
About free fonts:
Fonts by Blue Vinyl