On Mashable there is a list of 13 web-based word processing applications. All of the applications have collaboration/ sharing features. Click here to see the full list.
I tried out 11 of the applications (Google Documents and Zoho Writer were not new to me) and the one that really got me excited is Buzzword. Buzzword is very rich in features but at the same time has a simple interface perfect for use with students. Below I’ve embedded a short video overview of Buzzword.
Applications for Educator