There are numerous GIS/RS application developed for the Unix platform, but they are either expensive, either the user interface was not a prime requirement of these applications. Opensource GMT and GRASS are great applications but with poor user interface. A complete list can be found on http://www.freegis.org or http://www.remotesensing.org.
For the moment this project is its childhood, and has been released in its early stage to bring user support and more important developer support as soon as possible. You the have a real chance of making this project to your liking by suggesting as much as ideas as you want on the developer mailing list. You don't even have to code stuff!