The main XOP window has some PODS or TABS that can be used for different purposes
Just the logo
Permits a "static" access to XOP applications. Double-click on the application name for starting it.
A periodic table. Double-click on one element to display some x-ray related data.
Enter an IDL command, or application name (e.g., xplot). This permits to execute some command and/or to define some data. All data defined here is copied to the "IDL main level" and for further access in some applications (like Xplot "paste", or for inputing data in the iTools). For more sophisticating programming, use XOP_MACRO.
This helps to define the XOP Current Directory. It is very convenient to define a current directory (with write permission) , because:
All temporary files written by IDL will sit there
All applications will open, by default, at this directory.