Zoho Writer
Zoho Writer is a powerful online word processor to create and edit documents. With its Editor API, partners can integrate the feature-rich Writer Editor in their Web application and work on standard Microsoft Word and OpenOffice documents right from the web browser.
Zoho Writer has also released a new set of fine-grained APIs that helps users with document comparison, conversion, and communicate with Writer editor by posting messages from their web app.
Zoho Office Integrator for Writer supports all popular formats: .doc .docx .rtf .txt .odt .html .sxw