Yes (you can run ExtendSim on a Mac) and no (just not natively). ExtendSim is a Windows application, but there is a way to run Windows applications like ExtendSim on Macintosh computers.

Solution -- Install the Windows operating system (OS) on your Macintosh. To do this, you need to obtain the Windows OS and an emulator. You can use Boot Camp Assistant (installed with the Mac OS in the Utilities folder under Applications). Or install the emulation software Parallels (www.parallels.com). During installation, the emulator will request the Windows OS installer to complete the process. Once the installation of the Windows OS is complete, boot the Windows OS, install ExtendSim, and start modeling!