Dojo is a kitchen sink. Among its functions are rich user interface widgets, data tables similar to spreadsheets (with APIs for swapping large data sets from the server) and even a client-side template language.
If all you need is the browser’s animated, animated, and utility requests, use a simpler jQuery or prototype.
Dojo is like a high maintenance girl. She looks great, but you need to pay a lot of attention to her. Get ready: "I should not tell you why I am upset, you should know."