With the release of Firefox 3.5, all major browsers now support a version of @font-face font embedding.

The odd man out (surprise surprise!) is Internet Explorer, which only supports the EOT format, as compared to Gecko and WebKit-based browsers that support TTF and OTF formats.

However, this is not the big barrier remaining. It is fairly trivial to convert TTF to EOT. The bigger problem is that most fonts are not licensed to use on the web -- even free ones.

However, there are a number of reasonable looking fonts that are either public domain, or licensed under a variant of the Open Font License. The following are some of the best:

• MgOpen - Canonica, Cosmetica, Modata and Moderna fonts
• SIL - List of OFL licensed fonts
• DejaVu - extended fonts
• GNU FreeFont - one monospaced and two proportional fonts
• Open Font Library - 150+ fonts of varying quality
• Parabaik - the Parabaik font
• GhostScript - a large number of fonts but in PostScript Type format 1 (a job for someone to convert these to TTF/OTF, maybe?)

More information on the status of the Open Fonts and links to many more resources can be found here.