Blender is, unfortunately, a nightmare to get anything out of!
The file format is basically a C-side memory dump, and is to all intents and purposes unparsable by any client applications. It changes drastically between versions and is totally undocumented. Last I saw you could either output to VRML, or learn Python and write a converter into whatever format you want.
An XML file format has been suggested, but last I saw it had been shot down by a comment similar to "that would slow down loading/saving, d00d!!!". Sad really, if they used XML it'd really allow Blender to do more, but no.