Question: I am doing an pure AS3 programming, and I have urge to work with something like ArrayList because I need an array of objects (which in this case, array class is no use).
However it seems there is no ArrayList class for me to import (Flex has but ...)
I also found an open-source project called as3-collection on internet, but what the hell??? cant find any link to download...

Answer: 
If you really need the methods of the ArrayList you could have a shot at creating your own implementation.

ArrayList is mainly a bunch of methods with an Array as the backend, it simplifies interaction with the Array but doesn't seem to do things that you wouldn't be able to do with an Array.

If you're looking for easier manipulation of data, create your own class with the necessary methods.
You seem to be looking for [ArrayCollection](http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/collections/ArrayCollection.html?filter_flex=4.1&filter_flashplayer=10.1&filter_air=2).

If you'd tell me what you want to do with your array of objects then I could give you a more concise direction to how and what to do. It shouldn't be a problem.