Pretty straightforward. Open source is good, but organization and documentation is better. Actionscript 3 is a must, I don't really w开发者_Go百科ant to start working with the older versions. I guess that's the crux of my problem using Google, because there are vast quantities of how to do thing "the old way" out there, but I'm having trouble getting solid AS3/Flash9+ stuff.

And the point is shortening development time, so "in progress" or 0.x versions need not apply.

There are three that I'm familiar with:

flixel

flixel is a game framework that uses bitmap graphics. It largely sidesteps the Flash display objects so you don't need Adobe's Flash authoring tool to make games. It comes with some basic physics built-in: velocity, acceleration, and collision detection. Most of the games made with flixel have a retro, 8- or 16-bit feel since it's hard to do vector graphics.

This is the framework I've heard the most about, and seen used the most. It has a fairly active community and a lot of documentation. Most of the Flash entries for the recent Ludum Dare competition were in flixel. I think out-of-the-box it's the fastest start.

PushButtonEngine

PushButtonEngine is a component-based game framework. Basically, instead of objects inheriting behavior and properties from their base classes, they contain components that provide the desired behavior. Unlike flixel, PBE doesn't have built-in collision handling. You need to use Box2D for that, which strikes me as overkill for simple games.

PBE hasn't reached version 1.0 yet, and they're still re-organizing the codebase. This is a problem because tutorials for it rarely mention which revision of the framework they target. When I tried it out, I couldn't get any of the Box2D tutorials to work with the most recent revision. I would probably have had better luck with the last stable revision.

I should note that PBE is complete enough to make games with, but you may have some problems finding good tutorials and documentation.

Flashpunk

Flashpunk is a new framework similar to flixel. The main difference is the way features are organized. Flashpunk is set up similar to GameMaker, so if you're familiar with GameMaker, it will be a much easier transition.

I haven't tried Flashpunk myself; it's on my to-do list.

Physics Engines

These are used to add (more) realistic physics to your game. You can integrate them with the frameworks above, although it can be tricky. PushButtonEngine comes with a component for Box2D integration.

FisixEngine, mentioned by Todd Moses. I haven't used this.

Box2DFlashAS3. This has seen a lot of use, but usually not together with the frameworks I've mentioned. My main issue with it is that it's a port of an originally C-based physics framework, so the way things are organized is not very Flash-like.

ActionScript Physics Engine (APE). I found this better-organized than Box2D, though not as feature-rich. Still kind-of in development.

(Edit: Expanded with a section on physics engines)

flixel is a pretty sweet AS3 framework. It's the framework that Canabalt and a bunch of other games have used. I tried it out last month and it was easy to get started wtih, and based on the games that have been created, it doesn't appear to limit what you can do.

http://www.fisixengine.com/

is the most popular game engine for actionscript 3.

PushButtonEngine provides a promising game framework.

If you are looking for 2d games Flashpunk is a quite new one worth a look, I haven't tested it all though.

Love flixel, best way to start game making

Came across this thread and noted that most of the existing items were very outdated, so I'll add a couple more:

Starling

Starling is a must if you want to leverage the newer Stage3D APIs, which provide an enormous performance boost around render times. A lot of work has been put into multiplatform support as well, which is important at this stage. It is the most important tool to use as a developer making Flash games since the release of Stage3D.

Daniel (the author) is also very active on its GitHub page and the Starling forums and from what I have seen puts a lot of effort into reponding to developers with plenty of wisdom and enthusiasm.

Citrus Engine

Seems to be one of the more popular modern frameworks available; it comes with Starling support out of the box and allows you to select one of several popular physics engines. Based on my glancing at its GitHub page from time to time, I'm confident that it still has good support and ongoing feature additions at this point in time.

Sentinel

I am not sure whether referencing a project of my own is appropriate, but this is a game framework I have been working hard on for some time now. Its main features are tight integration with Starling and Box2D. My main areas of focus are thorough documentation and code consistency.

I've dealt with Flixel, and I just started fiddling with PushButton, which is looking pretty good, but has a bit more complexity than I really need at the moment. They're both good examples, though.

I have gone through and used recently Ash framework. Ash is a very high-performance entity system framework for game development written by Richard Lord. It can be used in 2D/3D game development. And I would like to suggest you to use this one.