Linux is not a widely used OS and until it becomes more end-user plug-n-play ready it won't be. Most of its current iterations require the user to know a thing or two about coding and spend a lot of time customizing it to get various software to work on it. Not something the average Poser user is going to bother with. Most high-end software doesn't even come Linux-ready, you have to make it so on your own. Windows or Mac are the two main OS's that the majority of software is built to run in. Emulators are available to fill in the gaps. There should be and N/A or Other option under the OS field and at the end of the survey there was a text box provided for any other comments that weren't covered in the survey questions.