I think Apple owns the trademark Firewire and indeed wanted royalites, I want to say $2 per use, but I could be full of crap.
Also, I'm pretty sure Apple devloped or co-developed the actual creation of Firewire, though if someone has more hard facts, I'd love to hear em.
Things brings on a whole issue of Firewire vs. USB (2 especially). I had been wondering why the hell a stupid useless interface like USB was propagating when a clearly superior option (Firewire) was well in place. And then someone reminded me, because Intel developed USB(2) (right?-codeveloped? owns? something like that).
Anyway, it's all about owning or at least being in a position of power with a given technology, which of course is why every damn stupid new thing is proprietary (e.g. internet video codecs, networking formats, cables, wireless protocols, etc.).
This is a shame because if there were more cooperation, we as consumers would be much better off. Anyone remember a little thing called MIDI? Introduced in 1984, developed by a consortium of music industry folkes, it set a clearly defined (albeit, a tad bit limited as it turns out, but still) set of rules for everyone to follow. It is still the standard today and many, many companies profited from its acceptance. The computer industry has no such MIDI metaphor that I can think of.
Exceptions occur, however. One recent one is Adobe with SWF files. They conceded the format to Macromedia, but simply went ahead and developed arguably better tools (or at least very good alternatives) for working with SWF files. This was smart as if they had tried to develop their own format, they would have wasted a hell of a lot of money, confused the consumers and probably would have lost anway.