Instructions tested and "complete". Enjoy! Thanks to those who tested for me.
Xastir continues to be developed, but with the advent of the iPad and RadarScope, my personal interest in Xastir has fallen off as a weather tracking tool. Those of you who still operate APRS computers and wish to overlay weather radar information on them are welcome to utilize Xastir. It served me well for almost 10 years. :)
Xastir is a open-source freeware application which runs on Mac OS X, Linux, and Windows. Xastir is a next-generation APRS solution that allows you to track APRS stations using a TNC or the internet, and plot them on maps of your choosing. Xastir allows you to combine this data with near-real-time weather radar data, so that an observer can tie in the APRS points with a radar image and a map, providing guidence for storm spotting.
I like Xastir so much because I can see the radar images, where the watches and warnings are, and a background map set to a detail level of my choosing. For my personal use, I disable the APRS station icons, so that I am looking at mostly radar.
While Xastir is a very powerful solution, there are a few things you need to keep in mind: the APRS data may be several minutes old, and the weather image data will be at least 7 minutes old. One should not look at a Xastir image, and think they are looking at "now". Even the best radar resource sites, such as the NWS radar pages, or sources like the Gibson Ridge software, still have data processing delays concerning the radar image.
Xastir is an awesome tool that could be used for net control stations seeking a tactical display of their spotter groups and the weather heading towards them. I personally use it for my own use, as it displays the weather watches, warnings, and radar imagery all in one location.
This guide was written by me to install Xastir onto a RedHat-like linux environment, with VNC, to allow for remote viewing using the VNC protocol. Xastir is very powerful software; I am certain that I have only seen the tip of the iceberg.