We are providing our own build of Structure Synth. It includes changes to Structure Synth's core that are required for exporting scenes to appleseed. Please note that this is an UNOFFICIAL build based on sources from a development branch, and as such it may be quite unstable.
This build, labeled Structure Synth version 1.0.0 ("Potemkin") -- http://appleseedhq.net/ Release, is based on the sources from the trunk of Structure Synth SVN repository, revision 261. It was compiled with Microsoft Visual Studio 2008.