mozilla is NOT netscape. mozilla is based on the netscape of four years ago, before netscape was bought by aol. Maybe they are the real reason for netscape's bloated shitness?
as i say, there's been a four year fork between netscape and mozilla (though until last year netscape did use mozilla code in it's browser, but not to any extent now i don't think).
Also, opera has a few features that mozilla should have incorporated a long time ago, which makes it the other major player in my opinion.