The SU package is not a graphical user interface driven utility at this time, though there are several possibilities including Java and TCL/TK scripts, which may be exploited for this purpose in the future. Because most commercial seismic processing packages are GUI-based, it is unavoidable that users will expect SU to be similar to these packages. However, this is not a fair comparison, for several reasons.
As mentioned above, SU is an extension of the Unix operating system. Just as there are no GUI driven Unix operating systems that give full access to all of the capabilities of Unix from menus, it is not reasonable to expect full access to Seismic Unix through such an interface. At most, any SU interface will give limited access to the capabilities of the package.
SU is not a replacement for commercial seismic packages. Commercial seismic software packages are industrial-strength utilities designed for the express purpose of production-level seismic processing. If you do commercial-level processing, and have dedicated, or plan to dedicate funds to purchase one or more license of such commercial software, then it is unlikely that you will be able to substitute SU for the commercial utility.
However, SU can be an important adjunct to any commercial package you use. Where commercial packages are used for production work, SU often has found a place as a prototyping package. Also, if new code needs to be written, SU can provide a starting base for new software applications. Indeed, the availability of seismic processing capability may encourage non-processors to experiment with processing, non-software-developers to experiment with software development, and non-researchers to engage in research.
SU is not confined to seismic applications. It may find use, both in geophysical and more general signal processing applications. It certainly can be useful for teaching students about ``wave related'' signal processing and, particularly, Fourier transform properties. This can include radar, non-seismic acoustics, and image processing, just to name a few.
Another thing that SU is not, at least in its current version, is a 3D package. However, it is not, expressly a 2D package, either, as there are numerous filtering and trace manipulation tasks that are the same in 2D as in 3D. It is likely, however, that there will be 3D applications in future releases of SU. A single 3D migration code appeared first in Release 32, which will hopefully set the stage for new developments.