Because it does not depend on other SEP software or geophysical software in general, xtpanel has been distributed through several public-domain source channels. Feedback from interested users has helped xtpanel to evolve to a reliable state in a short period of time.
There are several minor ways in which xtpanel could be improved in the future. Support of Motif in addition to the MIT Athena widget set would make xtpanel compatible with the software environments of more potential users. Because of the modular way in which xtpanel has been written, and because the Athena widgets and Motif have many features in common, adding Motif support would not be very difficult.
Another promising possibility is to be able to put images (pixmaps) in the background of xtpanel objects. If this were possible, one could, for example, very quickly build seismic tools that incorporate data picking, by having an image of the data in the background of certain interactive objects.