I just read some basics about Molehill, and I understood that learning an API is essential to gain some speed in the development, so far seems like Away3D is the winner, but Flare3D has some potential too. I know that this is too soon to know, but, if I want to get started with Molehill + some api, which one would be a good choice?
Thanks.
If you really want to learn a framework (which will obfuscate most of the actual Molehill stuff) I'm glad you have found Away3D to be the winner. Now, obviously I'm biased (as I am one of the core developers of Away3D) but we have a large community and the fact that Away3D is open-source, whereas Flare3D is closed source and charges $500 yearly per developer seat is probably the biggest advantage.
As far as engine features go, there are really not that many differences. Flare3D offers some more in the workflow department right now, but mainly just if you are using 3ds max. Flare3D is also very much geared towards game development, with physics et c integrated, but with little track record of creating neat interfaces and web experiences aside from games. Away3D is proven to be good all-round -- scene demos in Away3D have even placed at Assembly demo party at least twice ;). But lacks things like physics et c that are good for game development. Away3D strives to be a great rendering engine, and you can easily hook up an engine like bulletflash (a port of industry standard Bullet) for physics if you want that, but it doesn't come bundled.
So, Flare3D probably wins by a small margin in the game department, but only if you are fine with using their tools. If not, then it's probably a tie for games.
Actually, with the Away3D file format AWD, and one of the editors that supports (or will support) it, you can very easily create a game editor from your favorite 3D app. Last week me and a couple of team mates from Away3D created a playable 3D platform game with animated characters and one large game level (complete with physics) in about four days, and I did all of the level editing in Blender, including physics collider properties, spawn points et c.
So bottom line (if there is one ;)). Away3D is free and open-source (if you care about that sort of thing) and is a general-purpose 3D rendering library. Flare3D is a very promising, younger project that focuses on games, and has more of a "platform" feel to it where you only get the full benefit if you use their proprietary tools.
I hope this helps in your decision. :)