Recently Laszlo Systems announced their flagship product OpenLaszlo 3.0. OpenLaszlo is an XML-native foundation for building Rich Internet Applications and technically falls straight as a competitor for Flex.
The good part about OpenLaszlo against Flex is that it is free. But again that may be a misnomer, if you look at their cost of support, it will eventually make up for the cost of the application. For 1 year, a standard support will cost $15,000 whereas a Premium support cost $35,000.
The Flex components are still better than Laszlo. Development using either Flex or OpenLaszlo will be relatively easy for anybody familiar with a mark-up language. My personal adhearance towards Flex will be more of the fact that it can be easily tied to Flash Remoting, ActionScript 2.0 (and above).
For any developer or a company in Rich Inter Application Development, OpenLaszlo is another good arsenal for their RIA Development Toolkit. That’s it for now, more may come but I won’t promise.