Closest to a free Poser version must be the Demo of Pro Pack. It is available on CL's site (http://www.curiouslabs.com) and has limited functions for 30 days. It doesn't contain all the characters (but some) and you can't save your renderings other than taking a screendump of the final result. But it's a great way to get an idea of what Poser is all about :o)

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.