The Model Prototyper is a software tool which operates jointly with Rational Rose so as to provide an integrated prototyping and modeling framework.
In order to install Model Prototyper, you need the Microsoft JVM. This is however no longer available at microsoft. In the case the installer (ObjXPS_1.5.3.exe) does not find it, you can install the JVM (microsoftJVM.exe) before trying again.
The FacSimile.exe file is an experimental development of the OCL engine. You have to replace the FacSimile.exe file copied by the installer with this one. It first corrects a navigation bug (multiple collect navigation on * association ends). It also permits to write a rules.ocl file (in the same folder of the project - i.e. .prodsc file) which contains a list of invariants to check whether a given object is valid. The Menu "Tools/Reload the OCL Constraint File" permits to reload that file so that you can edit it and immediately integrate the changes in your OCL constraints to your prototype. Obviously, the file (so, your constraints) is not lost when exiting FacSimile, unlike the constraints you can evaluate using the OCL editor...