With MaximDL, The Sky, CCDStack, and Photoshop not operating under Linux, I feel that I am married to the Windows platform.
With today's Linux distributions and cheap hard disks, it is very easy to have a dual-boot machine. I strongly recommend this to have the possibility to work under both Linux and Windows on the same machine.
For example, the machine I'm writing this right now is a Dual Core with 4 GB of RAM and two Western Digital 250 GB SATA hard disks. The first disk has XP SP2 installed and the second one Fedora Core 6, where I work daily.
Another very interesting possibility is to build a pure Linux machine and run Windows XP on a virtual machine like VMWare.
Finally, it is always a good idea to ask the authors of the other applications (I refer to MaximDL, The Sky, and CCDStack, specifically) to write portable applications supporting Linux and Mac OS X. With the excellent development tools available today for cross-platform development, it is really quite easy. For example, for PixInsight we use Qt (
www.trolltech.com) to build its entire GUI that is 100% portable. Our core development tools (PCL library) are also 100% portable.