A complete game system derived directly from GURPS Third Edition - Revised. Incorporated the parts it needed from GURPS Basic Set, the two GURPS Compendiums, GURPS High Tech and GURPS Vehicles so as to make those unnecessary.
Never finished, but still occasionally releasing new material.
Still publishing new material in PDF after the release of GURPS Fourth Edition.
Since these GURPS WWII books can be used with any of the other GURPS line, we consider them part of GURPS 3rd and 4th and use this series to tie them together.