DeSmuME is a good Nintendo DS emulator for Mac OS X and Windows. Started back in the 2006 it has had many releases and updates with the last one coming from April 2015. It runs on C++ so, there are some required additional DLLs for the emulator to run. It can run almost all Nintendo DS, but there may be some bugs here and there. There is a stable platform for cheat codes and demo version for Wi-Fi support, but the owners advise to avoid Wi-Fi use.