in browser document editing- possible? How?

[iansilv]

I want to setup a feature on my site to allow my users to select from various letter templates and edit them to make letters for individual clients. The letters will merge some aspects of the case file in to them, and then save and store online on the server. They will also need to be printed out as letters them selves.

Does anyone have any suggestions on components that can make this happen? I am running asp.net with ajax, so anything anyone knows of that could do this would be very much appreciated.

thank you.