Which are the best scientific applications for Linux this year? And the best CAD/GIS applications?
Bricscad has made a remarkable effort in selling a Linux version of CAD software (while not free, it was something badly needed in our platform). While Bricscad is pretty much the only general purpose CAD reading the DWG format, there are other that do (VariCAD does but it's specifically optimized for mechanical works only), and there are other that even offer a free (GPL/LGPL) as QCad (and its clones); even though QCad is slow and unable to directly read DWG, there's a lot of things that could be improved. Cycas is fast, but its format is incompatible. But at least it should be known that Autocad is not the only alternative for engineers/architects who happen to be Linuxers and had to use Autocad in a virtual machine.
There is not a reliable structural analysis application for Linux yet, as far as I know. (I mean a SAP2000 FLOSS concurrent for instance).
We fare better on the GIS arena with Quantum GIS, GRASS and other applications fairly usable and reliable. I know many others, some discontinued, some new, some not free (qgis and grass are free software by the way).