The Europa series has been produced by four different publishers, as follows:
GRD began publishing play aids for Europa under a license from GDW, while GDW was still publishing the games. In 1989, they acquired use of the Europa trademark and began publishing the games, both new titles and "Deluxe Edition" revisions of previously published titles.
When GRD's Winston Hamilton died in March 2001, Mill Creek Ventures (principal owner Carl Kleihege) bought the rights and took over production of Europa. They continued using the terms "Game Research/Design", "GRD", and "GRD Games" alongside "Mill Creek Ventures" in their publications. They never published an actual Europa game, but they continued with the development of future releases and released several issues of The Europa Magazine.
In mid-2004, HMS bought the assets that formerly belonged to GRD, and thus took over production of the Europa series. HMS published the module Wavell's War in November 2005, and has released two issues of The Europa Magazine.
Under the terms of the agreement whereby GRD had obtained use of the Europa trademark, the intellectual property reverted to Rich Banner when Winston Hamilton died, so all Europa production by Mill Creek Ventures and HMS has been done under a license from Banner.