The main feature that the interpreter lacks that I wish for is arbitrary precision arithmetic.  Adding arbitrary precision arithmetic to the interpreter is not impossible but it would not be a trivial undertaking at all.  Much of the code would need to be re-written.

I'm  going to continue to study the code to assess the amount of work that will be involved.

Also I worked for nearly 1 week trying to create a GUI version of the program, but now I'm not sure if this is even possible.  The way the code is written all results are simply dumped to the terminal one character at a time from within an evaluation loop. 

If anyone has any interest in helping out please contact me.  The source code is in the form of Visual Studio 2010 Express C++ .

This weekend I was able to compile Hope as C++ code.  The Hope interpreter was written in C, and it would only compile with the C flag in Visual Studio.  The problem was with variable names, old C style function prototypes and functions that only C uses, all had to be changed. 

Compiling Hope as C++ is important because C++ libraries can be considered for use now, specifically in the area of GUI toolkits.

The first release of Hope for Windows did not work on Windows XP.
The new version 1.2.1 has been tested and it works on XP, so that problem has been corrected.

There was an issue with the function SetCurrentConsoleFontEx() which only works on Vista and above, so that function is  no longer used.  Also the interpreter was compiled statically so there aren't any issues about missing C library files.