New multiplayer dev, what should I use?

Hi all. I've been developing games with flash (as3) for just over a year now and I was looking into making a multiplayer game. I'm new to Nonoba and I see there is a Multiplayer API and this Player.IO

I haven't started with either yet, so is one better than the other? I don't know any server-side code, only Actionscript 3. And in a quick look at Player.IO I saw that there were plans which you have to pay for. Is the free Player.IO the same as the normal Nonoba Multiplayer API?

Sorry I have so many questions, but one last thing... can I develop multiplayer games on a Mac. This is what I am running Flash running on. I do have an older Windows computer, but it doesn't have Flash... In the FAQ it says:

"We are working on getting our development server running under Mono which means it will be available for all major platforms in the future."

Thanks in advance,
A truly appreciative Benolds

I used the Multiplayer API. Anyway for most game you don't have to do much work in the server side like you do in the clientside. Download the multiplayer API, and you'll have sample games of how things work. Test them and try to understand how things work in the serverside. I was new to both C# and actionscript to be honest, but it became easy when I played around with the sample games.