How to create a .blend file (out of Blender)?

I’m trying to make an export script for other application, but I would like to export direct to Blender. How can I create a blend file out of Blender using Python?

I encountered the same problem when I tried to export a rigged character from MakeHuman to Blender. The format of a blend file is described at http://www.atmind.nl/blender/mystery_ot_blend.html After some attempts one thing became very clear to me: although it is possible to write a blend file from your own application, you don’t want to. You just don’t. To write a blend exporter you more or less need to write a whole mini-blender of your own.

Instead I settled for a different strategy: I defined a custom exchange format, and wrote an exporter to this format for MakeHuman and an importer for Blender. The format I use is based on Wavefront obj, with additional constructs for armatures, vertgroups and shapekeys; depending on your needs, you may have to invent additional commands. The code can be downloaded from http://www.makehuman.org/forum/viewtopic.php?f=4&t=1041&st=0&sk=t&sd=a&start=10#p3381

How about you create an empty (or full) scene and then use the python Save api call.