These typefaces (and more) are presented, completely free, by The League of Moveable Type. They say:
We’re done with the tired old fontstacks of yesteryear. Enough with the limitations of the web, we won’t have it. It’s time to raise our standards. Here, you’ll find only the most well-made, free & open-source, @font-face ready fonts.
This revolution is not a movement against type foundries and type designers; it’s quite the opposite. The kind of revolution we want is a change in the way people think about doing business. We want type foundries and typographers to start thinking,
“Maybe there’s nothing wrong with giving things away sometimes.”
It’s not always about the money, sometimes it’s also about making a contribution to the society, in this case, the design community.
This movement is also supported by Ellen Lupton. You can find her explanation and more links here.