The plutext solution enables many users to work on the one Word document at the same time.

Why would you want to do that?

The way we put it in the Wiki:

1. Get documents finished ahead of deadline. Sales proposals, contracts, reports. Our focus is real time simultaneous collaboration – two or more people working on the document at the same time.
2. Plutext allows you to continue to use Microsoft Word as your editing environment. You know how to use Word (at least until you installed Office 2007 anyway..).
3. So you can format the document using Microsoft Word. If you did your collaboration in Google Docs, chances are you’ll have to bring it back into Word to make it pretty. Our collision handling is nicer to.
4. Work offline. It’s Word, after all.
5. Word’s docx is our native document format. So there is 100% fidelity. No numbering going haywire.
6. Complete version history / audit trail.
7. Don’t have Word? Coming soon … Use docx4all, our WYSIWYG docx editor – on a Mac, on Linux etc.
8. Oh, and its open source. All GPL 3 (Affero GPL 3 in the case of the server side bits). Use our server (developers only for now), or build your own.