Linux Systems Limited use nothing but Linux®. All of our systems are running a number of different distros, be it servers, desktop or laptop systems. The solutions that we provide, we are also using on our systems - so you have confidence in knowing that we also believe in the solutions we sell - because we use them too!
We tend to use a mix of distros depending on the task in hand. Performance and reliability will be another reason for the specific distro of choice, as well as feature availability.