When was the first Sony portable music player released, and when was the first one that supported anything other than Sony's proprietary formats released?
Uhm, 1979 and 1979? http://en.wikipedia.org/wiki/Walkman#Cassette-based_walkman
dirXML is still available, they just call it Identity Manager now.
"They that can give up essential liberty to obtain a little temporary saftey deserve neither liberty not saftey." -- Benjamin Franklin, 1759