Quark Matter '99 --- Theoretical Summary: What Next?

Berndt Müller

Published 1999-06-09, updated 1999-07-15Version 3

I review the three broad areas where major progress has been reported: The phase structure of strongly interacting matter, the properties of matter at the instant when it freezes out into individual hadrons in the final stage of the expansion of the hot fireball, and the status of the main signatures of the formation of a quark-gluon plasma. In the final section I present some thoughts about what should be done next, both in the experiemntal and the theoretical arena.