Q:
I want to integrate WebViewer into my Salesforce system. Is that possible?
A:
We haven't had much experience with Salesforce customization, but it seems like it should be possible.
For example, it seems possible to share Salesforce documents from a public URL:
If a document can be referenced using such a URL, it should be possible to reference the document from WebViewer.
Additionally, here are some techniques for embedding a custom document viewer into Salesforce:
If these viewers can be embedded into Salesforce, then it seems likely that it should be possible with WebViewer as well.
WebViewer references documents in a very generic way (just with a file path). All document changes are encoded as XFDF documents separate from the XOD document. So you should be able to treat the XOD document as static content, and treat annotations separately. This may be quite a bit simpler than embedding, for example, a Google Docs viewer for Salesforce documents (as the above link demonstrates).