A quick search shows that it is a derivative of Stockfish and is UCI compatible so it should work with Arena. Other than that, I don't know anything about it without reading more.
anybody heard of "SugaRfree" chess engine? How to use it?

I know about as much as Martin does. My guess is you got the source code but not the compiled executables. You'll have to wait until others start to do the compiles.

Here's a link going to some compiles for SugaR XPrO 1.0 32-64.
http://talkchess.com/forum/viewtopic.php?t=63159
Hi, don't know much about computers (I am running Windows and have Firefox btw) but since someone suggested the engine I was using (with ARENA) is old, went on search for better engines and got some recommendations including one for sugarfree engine. I went to its site but it's weird looking, and not sure if it works with ARENA. anybody know anything about the engine or how to use it? thanks.