The 1.4.2 version of HDemoLauncher for Mac was available as a free download on our website. This free software for Mac OS X was originally designed by Nil. The application lies within Games, more precisely Tools.
From the developer:
This is the Halo Demo Launcher, that has the following features: the first is being able to manage a collection of Halo Demo mods and being able to turn them on or off. The second feature gives you the ability to download and install mods. The third feature allows you to change game mods when hosting games. The final feature allow you to preview live Halo Demo servers and connect to any one of them.
You may want to check out more Mac applications, such as Reggie or zeroN64, which might be related to HDemoLauncher.