I would like to start a list of well-implemented interactive online web applications for young children (pre-school/primary). Of course I've known about Starfall for several years and am aware that it is being used by many parents and teachers. Still highly recommended for helping children to learn some very basic skills. Last week I discovered Kindersay, which is simple yet very effective and user-friendly. Today I found myself very impressed with Kerpoof which Oxford Hills teacher, Richard Byrne, reviews in depth in his blog.
What others should be added to the list?
Kindersay
Starfall
Kerpoof
PrimaryGames (See Richard Bryne's review on his blog)