The hard parts of writing a web browser are the rendering engine, the javascript engine, the transport layer and security code. The rest, comparatively, is trivial and there are cross-platform OSS libs for all of those.
etal got it right though -- Mozilla began as an OSS project in 1998, long before many of those libs were available.
etal got it right though -- Mozilla began as an OSS project in 1998, long before many of those libs were available.