Iron Crown Enteprises has released the Harp Sci-Fi Gamma book in PDF form. This book comprises the core rule book for the HARP sci-fi game.  They call it the Gamma edition because it’s after the Beta, but it’s not yet the final version.  The artwork is one component not yet finalized.  As of this writing, you can get the PDF for $21.00, which entitles you to the final version once it’s released.