What is .SD7 file extension?
Content package created for the Spring engine, a real-time strategy (RTS) game engine; contains game files stored together in a compressed .7Z format; can contain maps, graphics, AI scripts (.LUA files), and other game content.
NOTE: The Spring engine also uses .SDZ files, which store the package as a .ZIP file instead of a 7Z file.
You can see a list of software programs here on easyfileopener.org that can open this file type so that you don’t need to search for it on the web. You can then open your file with this extension using a software listed below.