We have an application called "Plotlog" (PLOT LOGistic) that reads files of item parameters (IRT's numerical item "properties"), accepts user input, and draws a variety of two-dimensional displays on screen. The application was originally developed in Pascal for the Mac OS circa 1988-1990. While the binary still functions under the current Mac OS (v. 9), and we have the source code and resource files, it can no longer be compiled or modified because there are no suitable current Pascal compilers. As a result, all the old application does is provide a "working model" (if one has a suitable Macintosh to run it on) of a modern piece of software that is highly desired. I receive email regularly begging for a "Windows" version; but the original never was portable, and with changes to software development environments the only real way to make useful modern Plotlogs (for various platforms) is to start all over.
(Alternate) possible goals:
1) Re-create the whole thing (or parts of it; it has discrete modules, and some sections are more worthwhile than others) to C++ or Java and a Windows user interface. Doing this has the largest (current) potential user community.
2) Same as #1, but target Mac OS 9. This should be easier, but for a smaller user community---although because it is largely an object of educational interest, the user community for a Mac OS version is still respectable.
3) For the forward-looking, re-create the application for Mac OS X(beta) in objective-C (Cocoa) or Java.
Question: Is Java really now sufficiently fast for this, and/or sufficiently portable that one development might run on both the Windows and Mac platforms? (Frankly, flavors of Unix are beyond the capabilities of our user community. ;)
This project (or these projects) can have the clearest a priori definition of any in this set of three, because they come with a working version of the application and the (old) source code, although the latter serves only to define the application precisely. The circa-1990 documentation is linked below, as a .pdf file (if it feels like working for you; I've had a bit of trouble with Adobe's latest greatest today).
A fairly crude block-diagram of (most of) the functions of the program is shown below. At this level of abstraction a good deal of complexity having to do with legacy file structures and the underlying equations of the functions that are plotted is supressed.