Is there anything mature enough to be used in a production environment? Or should I simply roll my own implementation for now and wait for the rest of the world to catch up?
As you said, the only ones I have found are either betas or alphas with none seeming to be ready for release.
At this point in time it is probably better to roll your own:
Better understanding of the internals.
Able to tweak the engine to your needs.
Develop the features you need to use
Skip features of other engines you don't need, reducing code bloat, and overhead.
Bugs and issues will be your own problem, and easier and faster to fix than an unfinished engine.
The Aves Engine was a really good engine (so it seemed), and then Zynga (Farmville people) bought it and made it closed source. There's a video of it being presented somewhere, before it was bought.
I agree, all of HTML5 is in beta, but lots of people are working on game engines. I'm doing one myself (which I'll release open-source and describe fully in a book on HTML5 game dev.)
So far, I've got a basic sprite object that works much like a MovieClip in ActionScript or a Sprite in PyGame. It's got all the basic features: speed, direction, vector-projection, multiple images, boundary-checking, transformations, and basic collision detection.
I'm working on a very simple game object as well. This will encapsulate the canvas element, manage the main animation loop, and provide high-level interface to the event system (such as it is)
I'm trying to keep it as simple as possible: something like gameEngine in Python:
Even when I get this working, it certainly won't be stable, because the underlying technologies are far too unstable. The browser support of various HTML5 features literally changes every day, and there is still no meaningful support for most HTML5 features in IE. Also, performance varies dramatically between browsers, so a game that runs great in chrome may not run at all in Firefox.
If you're wanting a stable, practical environment, HTML5 isn't it yet. If you're interested in experimenting with HTML5, it's looking like a very promising alternative. I'm definitely eager to use it as a teaching environment. I believe it will be pretty useful in that regard.
Personally I believe HTML5 to be downwards stable, i.e. what's there won't go again. Obviously no ones knows how all the unresolved issues will turn out in the end and yes, there might be features in the future that one should wait for, but it's already "good enough". That's why I guess a lot of people are working on their own html5 game engine or towards that. At least I am :-)
It does not have an isometric builder yet, but well, it does not stop you either. Tutorials will be added soonish, but mainly I am posting this cause I also listed all the other engines I found so far - here at the bottom http://blog.weeblog.net/?p=29
The following engines don't support ISO out of the box but are - from the kind of abstraction they provide - maybe interesting for you to read, or might even provide underlying code:
There's isogame that came up from google.
How about this one: http://code.google.com/p/jgen/
I would suggest taking look at LimeJS, seems very promising - http://www.limejs.com
CraftyJS supports isometric pretty well, and has examples on their site. Check it out: http://craftyjs.com/
I wrote an html5 game engine and open sourced it here: https://github.com/j03m/trafficcone
It supports an isometric world + sprites and is free.
Yes,You may find it in http://myospace.jp/about.php. I developed that Html5 based avatar engine. and I give it the name "MYO". I used it to duplicate the most well know Japanese Avatar system of "ameba pigg". It works on Iphone, android and of course WEB. but best on Iphone. You may try it yourself. if you want more info about it Please Mail me.