Robin is another set of classes form Flash Feathers.
It is used for multi-user purposes with the advantage of being for free.
It still is in its embryonic state, with a few bugs, but the more people use it, the more reliable it becomes, specially for educational purposes.

So, if you are in a basic level, give it a try, go the blog page and download all files you need.
Remember, you will need a PHP server running (XAMPP) and Robin.php running before jumping into actionscript.
This file is responsible for providing data for each real-time connection on the server. This data relates to some properties such as x and y.
Once you get a hold of this data you can update your application to meet your requirements. Read the documentation there are some methods available.

If you want other solutions for the same purpose, try Red5 and unity.
They are both paid I suppose but with more advanced setup and options as well.
Let’s not forget about Adobe products, there is the Flash Media Server which is very expensive, but it works well. I tried once a couple of years ago.

These technologies become handy not only for multi-user apps but for Live Stream Publishing and Recording, Streaming Audio/Video, Remote Method Invocation (RMI) and other techniques involved in remote communication.

Woodpecker is another set of classes from Flash Feathers to manipulate audio in Flash.
It uses the computeSpectrum method from Flash to change graphics.
By the way the Flash CS3 documentation page has a very clear tutorial explaining what this method does, it’s worth visiting.

One of the gurus in audio for Flash is Andre Michelle. He’s been working on stuff since the beginning.
Even before Flash introduced methods and classes for audio. Recently (March 24th) he came up with an app called AudioTool which allows you to create your music and mix it.
I’ve checked out some of his code and it seems very advanced, dealing with a lot o Math for wave signals and transforms as well.

Another fellow that dug into this world is Joshua Davis. You can check out HYPE which is a set of classes in actionscript for creative code, not only audio, but you will find the SoundAnalyzer Object, the Oscillator class and so on. Follow this tutorial to get introduced to it.

I hope all this is useful!

First time I’ve seen unit test framework for ActionScript.
Something we should all try sometime.
Created by Robert Penner.

AsUnit