Thanks , I already read it Jon . I agree with you that this offer is not clear at all . For me free is free. For example I had Vue 2 in "Computer art", it was free. Sometimes there are some special offers, some demos, it's always said " you can not saved more than 20 times" (rhino soft), or you can not build more than 60000 polys. In that case it's clear. ;=) Yves P.S. : xfrog seems interesting, maybe an old version will be available for complete free ;=)