The drug morphine derives its name from Morpheus based on its similar dream inducing power.
2. A file sharing client that has used the OpenNAP technology platform, but it seems to have broken compatibility as of lately. It has a web-based search interface, just like Audiogalaxy, though Morpheus searches all kinds of media, not just mp3.
3. A character (played by [Laurence Fishburne]?) in the science fiction film, The Matrix.