most commonly used Linux version?

[Jonathan Hutchins]

On Monday 23 May 2011 04:17:54 pm thomas at redhat.com wrote:

> We own between 65 and 85 percent of the Linux server market, depending
> on which report you read. Debian based distros are not really even a
> blip on the radar from a commercial standpoint.

Based on number of licenses sold, or total revenue?

IBM has a big share of the POS market, and their POS system is based on SuSE.    
They don't count the licenses on a per-terminal basis as far as I know, so 
their "market share" would be skewed too.  I know of only one very small 
specialty POS system based on RHEL.