Nestopia 1.4.5 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The application lies within System Tools, more precisely Virtualization.
Commonly, this application's installer has the following filename: nestopia-141.dmg. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The most popular version of the application is 1.4. The unique ID for this application's bundle is com.bannister.nestopia. This free software for Mac OS X was originally produced by Lucerne Systems.
From the developer:
Nestopia is the current king of the NES emulation hill. It uses highly optimized cycle exact emulation, allowing it to run titles that rely on precise timing, many of which break under inferior emulators. This accurate emulation does come at a cost; Nestopia requires a minimum of a 600MHz machine for full speed; but if you have one, this the best available NES emulation for Mac.
You may want to check out more Mac applications, such as VMware View Client or Nox App Player, which might be related to Nestopia.