Mozilla released Firefox 3.6 this past Thursday, January 21st which includes a significant feature in terms of web typography improvements. This update now supports a new font format called Web Open Font Format or WOFF. Prior to this release, Firefox only supported TrueType and OpenType fonts. According to John Daggett, a Mozilla contributor, WOFF has two major advantages over TrueType and OpenType:

1. WOFF is compressed meaning you’ll see smaller download sizes compared to the other two font formats. I believe this means FOUT (Flash of Unstyled Text) will occur more quickly.

2. WOFF contains information allowing you to see the font’s origin. This particular feature has helped the new format gain the support of several foundries.

So what does this all mean? The adoption of WOFF will eventually encourage the creation of more web-licensed fonts giving designers and developers greater control over their web typography.

If you’re interested in playing with this new feature, go ahead and update your Firefox and check out this CSS @font-face guide by Tim Brown, the new Type Manager at Typekit. Here’s a great source for 10 free fonts if you’re wanting to just experiment. And if you really want to make you life easy, Font Squirrel is a great tool that will automatically generate your @font-face kit complete with the various font formats requested, a CSS stylesheet and a demo. Pretty sweet! One thing to note, Firefox 3.6 is currently the only browser supporting WOFF so be sure to include the other font formats in your markup.