First, I dug into the Java EE app server data and like Rich fixed some of the grouping, specifically trying to get proper JBoss and Tomcat numbers. Our numbers differ a bit as I think he may be double counting a bit for Tomcat and JBoss which I made sure not to do.
I've ignored Jonas/JRun/Jetty/Orion so the other likely represents GlassFish and Geronimo. My chart shows JBoss behind WebSphere but ahead of WebLogic.
Since multiple answers were allowed though, it is interesting to see which combinations are most common.
Here, Tomcat is clearly the preferred second app server in a dual strategy, but perhaps surprisingly, there is a fair number that have both WebSphere and WebLogic.
Last, I took a closer look at the operating system data. I first combined the different Linux responses into a single one.
As I mentioned in my earlier entry, Linux usage is nearly surpassing Windows and Solaris is well behind those two.
Next I looked at what operating systems were commonly included in the same response.
Not surprisingly Windows and Linux are the most common combination and the combinations with Solaris fall behind with Linux and Solaris slightly behind.
These results may match what you'd intuitively expect, but it is always good when the data backs up your intuition.