AMCAD Engineering is powering the IVCAD software platform for Maury Microwave.
Recent advances in VNA based load pull have been plublished in Microwave Journal (February 2011).

Introduction to measurements for power transistor characterization, F. De Groote, J.P. Tessier, T. Gasseling and All, IEEE Microwave Magazine, vol. 9, Issue 3, June 2008, pp70-85 (Download PDF - 2Mo)