This paper describes our experience in applying a generic Intelligent Tutoring System (ITS) authoring tool to specific training applications. The Internet ITS Authoring Tool (IITSAT) was developed to decrease the time to develop tactical decision-making ITSs and was based on the experience from several previous ITS projects. IITSAT allows ITS authors to organize course principles, articulate teaching methods, specify courseware, and develop a case base of scenarios for students along with a s pecification of how the student's actions will be evaluated and his mastery of the required knowledge assessed. Evaluation of the correctness of actions and inference of the student's knowledge may be performed by external code, or with libraries supplied with IITSAT. They support both the use of finite state machines (FSMs) to evaluate a student's actions in a free play simulation, or comparison to correct and likely incorrect solutions for each scenario. Different instructional methods can be chosen including who should control the sequence of instructional events - t he student, the author, or the ITS, and what that sequence should be. The FBCB2/Tactical Decision-Making ITS prototype teaches armor company commanders by presenting course material and examples, then testing the commander in tactical situations displayed as F BCB2 overlays or in a commercial tank simulator interfaced to the actual FBCB2 software and the ITS. IITSAT's comparison libraries successfully evaluated a student's battle plan with the addition of domain-specific code. The next ITS to be de veloped with IITSAT was an F/A-18 Air Tactics ITS prototype which intelligently evaluated a pilot's actions during mission rehearsal to practice perishable skills. IITSAT was interfaced to ACM, a commercially available flight simulator which was altered to output a log of actions and events. FSMs evaluated the correctness of the pilot's actions and inferred mastery of different principles. The Air Tactics ITS was developed in a small fraction of the normal time and IITSAT did not need to be modified, but FSMs were less general than planned. An authoring tool was very helpful since it could be modified to increase its generality and flexibility.