its called "green grapes" some tomato website says: This old-fashioned tomato is an heirloom originally developed by the Tater Mater Seed Co. from crossing the Yellow Pear with Evergreen. The distinctive, 1 inch, yellowish green fruits are borne in clusters of 6-12 that resemble large muscat grapes. Fruit has a translucent pale-green on the inside. This variety has become popular in restaurants and markets because of their unique attractiveness and great flavor.
which makes sense, plants grow pretty slow. well, my tomatoes (tomaters?) have ripened some, the black prince tomatoes are now sort of squishy and browny/purple.