Some topics in the theory of jets are reviewed. These include jet precession,
unconfined jets, the origin of knots, the internal shock model as a unifying
theme from protostellar jets to Gamma-ray bursts, relations between the
Blandford-Znajek and MHD disk-wind models, and jet collimation in magnetic
acceleration models.Comment: To appear in Highly Energetic Physical Processes .... (IAU Symp 195)
P. C. H. Martens and S. Tsuruta, ed
