There is *probably* no NCSA mosaic code in the product --- they did a
deliberate from-scratch rewrite in an attempt to avoid having NCSA
come after them for royalties. It didn't work --- NCSA (actually
UIUC, I think) sued anyway, and though the Netscape folks thought the
suit was groundless, they gave the university a hefty chunk of stock
anyway to make the lawyers go away. (You may still be able to find
the press coverage of the lawsuit lying around in some deep archives).