Our desktop fonts come in the OpenType (.otf) format (with PostScript outlines if you wanna know it all). Our webfonts come in several formats. Our mobile fonts come in the TrueType format (.ttf).
Probably superfluous, but euhm… OpenType fonts are cross-platform, you can use the same font file through your entire workflow, from Mac to Windows and back.
Although the TrueType fonts are not implemented in our webshop, we’ve got TrueType versions of all our fonts as well, which we can deliver by email after you’ve bought a license through our webshop. Just contact us by mail in case you need the TrueType versions.
Webfonts currently come in 4 formats: .eot, .woff, .ttf and .svg files. This might change in the future once there is less need for some formats. Eventually the .woff format will likely be the only available webfont format, and will be supported everywhere. But there are still some old browsers around: http://caniuse.com/woff
Read more about font formats, webfonts and other technical issues in our support section.