Install SCID. It's free, it installs easier than commercial software, and free engines are stronger than almost every commercial engine these days anyway.
Shredder for Mac

I use Shredder 12 on a macbook. There is nothing extra special about it. I have used it to create opening study databases and do annotations of my games. Now that I have chessbase on my PC I barely use it anymore, since chessbase is a far better program for those things. If you're just looking to analyze your games and do annotations, I don't think its necessary to spend the money so long as you get a free engine with the standard annotation/database features.
Managing databases of your own games is slightly easier in chessbase. And, of course, if you pay for the big database you can compare the way you play your openings with a large body of theory. I think its a nice way to learn openings while annotating your games. For instance, I dumped around 800 blitz games onto a chessbase database file. From there, I can compare the games against the main lines and see when the game moves out of theory or into less played lines. When this happens, I usually do some quick mouse click research, and punch in a more preferable line. Also, you can choose to turn on a chess engine at any time when annotating your games. So, when I miss something or blunder, I make a note on that and think about why I made the mistake. I think its an efficient way to annotate games and fine tune my openings at the same time. The openings database in Shredder is smaller, but also useful for this process. However, I find the interface and array of options in chessbase to be a little better.
I got it for my birthday. I love it, but it's hardly necessary :-).
It's been a number of years since I had a commercial engine, but I don't recall it being any more intuitive than scid. I suppose there might be something to be said for the fact that it would come with a nice, handy set of paper instructions where you can look things up you don't understand. But that would be only marginally easier than asking on here.

Hi Folks,
I just bought Shredder 12 (single processor version) for my MacBook Pro. I am wondering if I can use the Shredder engine in other GUIs (like Sigma Chess, for example, or the new Stockfish GUI). I can use my other engines in Shredder, but not vice-versa. I can't find the engine file in the Shredder folder, just the app that launches the Shredder GUI.
Also, does anyone know if you can do a search of a database for a position in Shredder? I've been using Shredder to set up my opening repetoire, then switching to Scid to search my large game database for games in that opening. It would be easier if I could just do that inside of Shredder.
Thanks!
I'd love to hear from any Mac users here who have installed Shredder 12. . .
I think I'm going to get a new macbook pro and would NEED some quality chess software to install. Any and all info from the Mac crowd would be great. Thanks!!
-Ted