1) The Elves, or some of them, have a power (we can call it "magic", although
Galadriel would probably express perplexity at that), that can make items with
certain... properties. Like the Rings - let alone their swords. I do not regard
it as a technology, as I feel that it is something at least in part dependent
on the maker. Physics in Tolkien's universe do not work according to the same
way as it does in ours.
2) Probably lots of them, although some are more powerful than others.
Glamdring I would guess would be pretty powerful. Ringil would probably be
more. Narsil is not an Elven sword, so it might not have that particular power
- but I do picture Elendil wielding white fire against his foes when he handles
it. With Anduril, there is a gout of white flame every time Aragorn smites
somebody.
