The
Nintendo 3DS Citra Emulator is getting real online functionality support a few months away of
Nintendo shutting down online services for the Nintendo 3DS and Wii U consoles. While this feature is still not available in CItra Nightly or Canary due to the developer team consulting with lawyers the legality of providing this kind of functionality, a fork has been made publicly available which allows connecing to Nintendo Network. Among other things, the following features are implemented:
Managing friends, which includes getting a friend code that can be shared with real 3DS users.
Playing online in most games that support it, including with real 3DS users.
However, keep in mind that some features such as NNID settings or miiverse are not available. Support for alternative networks such as Pretendo Network is claimed to be added in the future. Installation instructions are provided in the fork's release page.
Release page
Video showcasing Mario Kart 7 going online.