There was a quiet additon to the popforge repository. It is our own file format to put your library in a single file. Basically it is just like a zip file. The format is built buy a header, item headers and items. This way it is very easy to navigate through the file and also allows easy streaming access.
At the end it is just a container format that is simple to use. There is a prototype AIR GUI to create the files and then you need one line to transform the file into a simple furnace library which gives you access to all your files again.
I appended the file specifications to the FurnaceFormat.as file for now. Any suggestions are welcome. Checksums are one thing we definitly want to include in the next version.