I\'m using docx4j to convert a microsoft word document into a pdf then displaying it in a browser http://www.docx4java.org/trac/docx4j and it works well for a preview. The probl
Have a play with http://converter-eval.plutext.com/viewer.html
Consider it an alpha level preview. We haven't quite released it yet, but you will be able to host it behind a firewall.
It isn't open source, I'm afraid, and we're still working out pricing (and whether/how there could be a free edition).
If you only need to render a docx document in a browser, u can use Google Documents Viewer for this as :
<iframe src="http://docs.google.com/gview?url=pathOfDocx&embedded=true" />