anyone know where to buy/download Halo CE??? (mac)

Seriously been looking for a place either online or in store to purchase or perhaps download a copy of Halo Combat Evolved for my Macbook... Help! Please :)

I own a copy, but I got it many moons ago.......... I purchased it from Amazon.

There are heaps of tuts of youtube. Thats where I got mine from and it still works. Make sure you read the comments and follow all the steps. I would refer a link but I got mine over a year ago, and I can't find the video :( Good luck