Following the release of Irrlicht 1.4, the package for Mac OS is now available as well: download Irrlicht 1.4 for Mac OS 1.4.
The dmg file contains all source files but no precompiled binaries, you need to compile it yourself using XCode. It was created by Varmint, and we are happy to announce that he now joined our team to keep on maintaining the Mac OS version of Irrlicht.