web-socket-js

It does seem to be the most commonly used WebSocket polyfill around. We also use web-socket-js [1] for fallback. But Version 3.0 of pusher-js [2] will remove that. One negative with SockJS has been the complexity of the fallback approach on the client (the browser). Especially when it's only for 8% of connections. A single simple cross-browser HTTP-based transport would remove the code complexity and reduce the file size. [1] https://github.com/gimite/web-socket-js [2] https://github.com/pusher/pusher-js/tree/r3.0.0

I'm the author of Phoenix. I'm glad to hear you're giving it a look! I spent a lot of time thinking about the WS layer and fallback support. Ultimately I settled for standard WS with a small multiplexing layer on top. For those that need fallback, they can drop in websocket-js (flash fallback, compatible with native WS api). Have you taken at look at this for your fallback support? https://github.com/gimite/web-socket-js Phoenix is still far from 1.0, so any and all feedback is welcome.

Excuses, excuses ... Detecting required features by browser identification is not only so 90's, it's downright ridiculous. All it takes to detect websockets is: if ('WebSocket' in window) { /* Web Sockets supported / } else { / Web Sockets not supported */ } Ironically, this was taken from: http://dev.opera.com/articles/view/introducing-web-sockets/ Also, every web developer with half a brain can use https://github.com/gimite/web-socket-js instead of locking out users unnecessarily by matching the User-Agent.

You could fallback to a Flash implementation of WebSocket, and use the native browser implementation when available: https://github.com/gimite/web-socket-js

https://github.com/gimite/web-socket-js is a good fallback which uses Flash Sockets. Whether you can use them or not really depends on your target user. I'd argue that for the general public you can use them; they'll be using IE with Flash, Firefox or Chrome. With the latter two you'll have native WebSocket support and with all three it's highly likely that all with have Flash installed. Things are trickier for corporate users where it depends on the corporate IT policy. As ever, there are edge cases.

One issue with this approach is that the author is allowing users to start the background work, rather than putting it into a queue like he had been doing with his prior site. If his site gets slammed, this will be a problem, whereas with a queue he could set up his interface to let the user continue browsing the site while his/her work makes its way through the queue. One nice find from the article is the link to the Flash implementation of websockets: http://github.com/gimite/web-socket-js

Ah, true. However, non-standard browsers can theoretically be supported by passing through a Flash plug-in: http://github.com/gimite/web-socket-js I suppose the ideal scenario is a backend which is capable of supporting both Comet and WS, depending on the browser capabilities.

There are also Flash shims available on the client side, so you can use a WebSocket API that falls back to Flash on legacy browsers: http://github.com/gimite/web-socket-js

You can use a Flash compatibility shim to make your sites use Web Sockets in some browsers and Flash sockets in others: http://github.com/gimite/web-socket-js This is the best of both worlds; Flash works for IE users, and Web Sockets will hopefully be available soon in plenty of non-Flash browsers (like the iPhone).