Oh, absolutely. That was their beef with Netscape, way back when: Netscape was a platform for delivering apps independent of the OS. NS was very explicit about it, talking about "crossware", applications written in HTML+JS+Java that would work on any OS where Netscape ran. It was premature—NS's one big crossware app, Netcaster, was slow and clunky—but still very scary to anybody that sold OSes.

(Edit: actually, it probably wasn't scary to any OS vendor but MS; the others were all happy to think that users might move to applications that could run on their OSes, too.)