ts>  No, you just need to have the header files and libraries for tcl/tk and
ts>  tk.h need the header files from X11

Ok, I'm a bit ashamed to tell you what my problem was.
I thought I had xdevel.rpm installed, but what I had was xshared.rpm
Everything went a lot better with xdevel :)

Now I've succesfully installed Ruby/Tk and Ruby/GTK on my Linux computer.
I still haven't found out how to install Ruby/GTK on Windows though.

And my first question is still there...
Do you recommend Tk or GTK?

Thanks for your help

Henrik