Flex 2 is not discussed in the 'pro web 2 development book'. The authors evaluate most of the other web 2 UI technologies (various Ajax frameworks, mozilla xul, etc). With adobe behind flex, given that it is free, given that it is a very thorough, all-encompassing UI technology and development toolset and the fact that the rendering engine/runtime (flash) is capable of far richer graphics rendering than the browser's HTML- based rendering (on which ajax frameworks rely), it seems a VERY compelling technology for developers to make a more 'complete' shift to building next generation web apps. I would very much appreciate a view on Flex 2 from some of the authors of the book.

You are making a good point. It remains to be seen if Flex really picks up, but this is for sure an interesting piece of technology. Do you have suggestions for books or online resources about Flex that you have found useful? Those would certainly be a nice complement for those who have ready the book or are just browsing on this forum, and would like to learn more about Flex.

Alex

Orbeon Forms - Web 2.0 Forms for the Enterprise
http://www.orbeon.com/

Flex.org is pretty comprehensive- there are loads of pdf guides covering all aspects of flex development. Flex also has an IDE (Flexbuilder) that is not free (+- $500 for the basic one and +- $900 for one that supports charting)that can be downloaded from the site (for trial period). The IDE works either as an Eclipse plugin (latest Exclipse i.e. 3.2 works best I discovered) or as a standalone tool. Anyway, I would try out the IDE to get an a feel for the kind of productivity that is ultimately possible with Flex. In itself, it (help facility) contains substantial documentation. It also has full debugging capabilities- you can actually step through your client-side action script code!. Even without an IDE, Flex development seems simple. MXML (flex's UI markup) seem a more intuitive markup than XUL and it's variants. I think it's closest match is Microsoft's XAML. As yet I'm experimenting only, but what I've seen so far almost convinces me that this will be my next first-choice web UI platform. Part of the appeal of Flex, is the simplicity- Macromedia development tools are traditionally not 'hardcore' developer centric, similar to Microsoft philosophy with development tools; they make it very easy to develop apps. I've been developing in Rails for the last year and developed my own UI libraries with server-side ruby API for things like trees, grids, menus and forms with which I can fairly rapidly develop web2-ish apps, but I am pretty sure that I'm going to drop that stuff in favour of Flex. Just a last comment(why not ajax): Microsoft's new XAML coupled with WPF/E is very similar to Flex: i.e. a way to provide rich rendering in the browser (all browsers supported) via a plugin. So it seems that some of the biggest players in the industry are not relying/investing on Ajax to support their vision of next generation apps. Ajax seems like an interim sollution, it originated almost by accident- whereas technologies like Flex and XAML/WPF was designed from the ground up to support a fundamental new vision of what applications should look and feel like.