about us


DENNIS FISHER and STEVEN SHAFER are both anesthesiologists by training. Dennis spent 20 years at UCSF, working closely with Lewis Sheiner and Stuart Beal, the creators of NONMEM. He now consults full-time in the area of pharmacokinetics, pharmacodynamics, and pharmacometrics; his consulting firm is "P Less Than". Steve has spent most of his academic career at Stanford University and also worked closely with Sheiner and Beal. He is presently Editor-in-Chief of Anesthesia and Analgesia.

In 2003, Steve started teaching a NONMEM course. In 2005, Dennis joined the course, now entitled Fisher / Shafer NONMEM Course, taught 1-2 times / year in the US and abroad. As part of that course, Dennis provided extensive graphics scripts to the enrollees and Steve distributed an operating system script "go" that runs NONMEM, creates graphics, and manages files and folders ("go" is based on a Unix script "doit" developed by Dennis).

In 2006, we decided that the NONMEM user community would benefit from a graphical user interface to manage the entire NONMEM analysis process. PLT Tools is the amalgamation of these various scripts into a graphical user interface (GUI). We are pleased to offer PLT Tools as the first comprehensive software tool to facilitate NONMEM analyses.


  • Alison Boeckmann, the programmer for the NONMEM Project Group for most of its existence, has been a remarkable resource to both of us. The "Brief Summary" provided with each NONMEM run and the "Summarize / Report" tool would probably not exist without Alison's development of the "nmsee" software.
  • Michael Diehr (Xochi Media) and Joe Strout (InspiringApps) developed the graphical user interface.
  • Zachary Fisher and Jeremy Fisher provided invaluable help in web and GUI design.