Projects like Shashlik or Genimobile use an emulator to run the Android environment. The emulator creates an entire emulated system which has its own kernel etc whereas Anbox runs the Android system under the same kernel as the host operating system does. There is no emulation layer like QEMU necessary. Everything runs directly on the hardware. This approach also allows a much better integration with the host operating system.
http://anbox.io/
or
https://mm.gravedo.de/blog/posts/2017-04-10-introducing-anbox/