Many other hardware players are available. All methods use lossy compression. The highest compression uses perceptual coding methods that eliminate effects that can't be perceived by the listener. Streaming is permitted by breaking the file up into smaller segments. Playing can begin after one segment is fully received.
Boundary distortions depend on the degree of predictive coding.
Some newer streaming methods use TCP because of the firewall problem. Late packets are discarded in audio streams. If there are too many late packets, the buffer size is increased. Top of Page Real Networks was one of the companies targeted by Microsoft during its crusade to crush competing technologies. MS recently offered to sell its WindowsMedia technology to Real Networks.