Sorry - not Java. I was using good old Visual Studio 97 when I wrote the first version, so I've just continued using it. I've considered porting it to .NET, but the benefits seem to be lacking.
BTW, the program has a nice undocumented feature or two (actually documented with tool tips), such as - you may enter fractions in most of the fields (example: you can enter either 12.75 or 12 3/4).
I wrote a German language version too, and it also has undocumented features. It allows you to use either the comma or period for the decimal point. Example: you can enter either 12,75 or 12.75. It's always been hard for me to avoid including "goodies". The problem is you never know what's going to turn out to benefit the user...