I really like MathCast - it is a great application. Have you considered porting it to Linux? Unfortuantely there are hardly any free MathML editors fdr Linux and MathCast would be perfect.

I tried to run it with Wine (www.winehq.org), but unfortunately it crashes when I try to open files and doesn't display equations.

Perhaps compiling it as a default linux application with Winelib would be a better idea. I think Winelib implements most of the Win32 API and was successfully used for porting several Windows applications.