Dune Legacy

Dune Legacy is an open source remake of Dune II that can run natively on modern systems (Windows, Linux, Mac OS X, MorphOS). The project is hosted on SourceForge since 2003. As of 2018 it reached version 0.96.4 (dated 2016-12-27), and is fully functional. It requires the .PAK files from the original game, and uses the same graphics and sounds. You need to own the original game separately, so there is no copyright violation.

Dune Legacy has mostly the same gameplay of the original game, but adds a modern interface, including multiple unit selection, building queue, zoomable graphics. Some new features, such as fog of war, are optional. The most notable differences in gameplay are: The three original campaigns of Dune II are available, plus the three of the classic mod Super Dune 2 (Fremen, Sardaukar and Mercenary). Custom games can be played on single-player or multiplayer over LAN or Internet. They allow battles with up to 6 houses (the original three and the three from Super Dune 2), combined in any sort of teams, on predesigned scenarios. Computer players in custom games have a full AI capable of creating a base from scratch, just like human players. The game includes a scenario editor with random terrain generator.
 * Infantry can be freely combined in 1-5 men units.
 * Ornithopters do not attack automatically, they can float in midair and be fully controlled by the player like other units.
 * Buildings and slabs can be placed one square away from other buildings and slabs.

Official site
http://dunelegacy.sourceforge.net/website/