The program is very simple without many distractions. Students can simply start mapping without signing in. However if students create an account, they can log on, create maps, save maps, share their work, work with each other, print, export as images, send their map as a web link, and access embed codes. They can only collaborate with someone, if they have an account and the person they wish to work with has an account.
The really nice thing about this tool that I really like is that it allows you to embed the map on your class web page. Fore example, the map below is one my students created...
(use the + or - buttons in the top left to zoom in or out)
Home Page Gliffy Info Mindomo Info