Sub Categories:

De Long's Wine Grape Varietal Table
Offers information about 144 varieties organized in an interactive table. Also sells a print version of the table.
Enjoying Viognier
Features news and information about Viognier, a wine of the month, and a searchable database of retailers and prices.
P.S. I Love You
Industry organization dedicated to promoting the Petite Sirah grape. Includes a history of Petite Sirah, articles, a list of members, and recipes of suggested food pairings.
Pinotage Association
Association promoting South Africa's Pinotage. Contains a history of the grape, winemaking information, and a producer list.
Zinfandel Advocates and Producers
Non-profit organization dedicated to promoting Zinfandel. Contains information about the grape, membership details, and a list of events.
ZOW - Zinfandel on the Web
Contains tasting notes and links to Zinfandel-producing wineries.