Aspyr

Aspyr is a software company, founded in 1996 and based in Austin, Texas, that specializes in creating native Mac ports of Windows computer games. Among Aspyr's products is the Mac port of SimCity 4. They released a port of the base game on June 20, 2003, followed by the Rush Hour Expansion on September 4, 2004. In 2014, Aspyr re-released the port of the full SimCity 4 Deluxe package on the Mac App Store and Steam.

The port is essentially equivalent to the unpatched WIndows version, 1.1.610. There are no Mac versions of the EP1 Update patch (1.1.638) or the BAT nightlight patch (1.1.640), and Aspyr has no plans to issue them. The release of Network Addon Mod Version 32.1 in July 2014 does address some of the transit path issues present in the unpatched Mac port.

Universal Binary Support

The original port of SimCity 4 was designed to run on PowerPC Macs. In 2007, anticipating Apple's eventual removal of Rosetta, the compatibility layer that allowed PowerPC applications to run on the newer Intel Macs, Aspyr released an unfinished "open beta" of a "Universal Binary" patch. The 2014 re-release incorporated a finished version of Universal Binary support.

The Universal Binary had issues with the encoding of some Exemplar files in some custom content, most notably, several critical files included in the Network Addon Mod, which caused crash-to-desktop (CTD) issues. The issues began to become commonplace after Apple released Mac OS X Lion (10.7) on July 20, 2011, the first release which did not contain Rosetta.

Due to the lack of availability of the Mac port at that point, and the complexities these changes caused, the NAM Team dropped support for the Mac platform with the Version 30 release in September 2011. With the 2014 re-release of the port, however, the NAM Team revisited the issue, producing a compatible version, NAM Version 32.1, on July 28, 2014.