Makerfarm provided the source to their Makerfarm i3 printer (a lasercut variant of the Prusa i3 printer) in a closed .pwj format. I have converted it to a more open format for those of us that wish to view the file. The source is provided in svg, pdf, and dxf formats.
If others encounter a .pwj file, it can be opened with a program called LaserGRAV: http://www.thunderlaser.com/technical-support/downloads/category/software-download.html LaserGRAV can then export the file in .plt format, which in turn can be opened in Inkscape and converted to whatever format you require.