Adobe Typekit was the first service to launch and was a complete game-changer for many designers, who then flocked to the service in droves. It has always had very user- friendly search, as well as one of the best blogs for both inspiration and education. Like the other sites mentioned here, Typekit supports OpenType features on select typefaces. While at this time there isn’t an easy way to know what fonts support them or which features are supported on a given typeface, that seems destined to change. Elliot Jay Stocks, creative director at Typekit, let me know that the team has plans for the very near future to highlight and utilize OpenType features to a much greater extent.