@Mapperz thanks for the heads up Mapperz. I don't look in on Bill Dollins often enough! For those needing some more context before the link is interesting enough to follow:

Bill Dollins revisits an "analysis of tags on GIS StackExchange to see what people were talking about on one of the largest and most successful vendor-neutral discussion sites in our industry." Numbers, pretty graphs, and source code -- Mmmmm. What's not to like? blog.geomusings.com/2013/09/12/…

Result? qgis is on top, opengeo is very active, while arcgis and it's associates remain strong, probably still predominating overall due to sub-tags like arcgis-server, but the real take away is that in aggregate GIS.stackexchange.com truly is an open multi-vendor environment.

Also see meta.gis.stackexchange.com/questions/3333/… where a closer look is being taken at Dollins' analysis, bringing caveats and relevant interpretive cautions to light.

@mattwilkie Possibly a more interesting investigation would look at the appearances of new tags and track their use over time. This could be a leading indicator of new trends within GIS, assuming early adopters actually come to our site with questions or solutions. I first became aware of a lot of software when it was mentioned here.