Programing suggestions

[Linda]

I have worked with text based C++ programs for the last 25 years. Data 
is mostly stored in data files that are separated by a specific 
characters and are locked when accessed to ensure file integrity. It has 
worked very well for our older employees. I spent the last year redoing 
all of our printed output so it creates postscript files that the 
programs can convert to pdf as needed to email customers. After taking 
on postsript I was thinking about playing with graphic xwindows programs 
so that the younger employees could work in an enviroment they are more 
comfortable with. Any suggestions on what I should start playing with?
                             Thanks
                                 Linda