Now that Flash is part of Adobe Systems, AJAX is omnipresent, and Microsoft and Sun have entered the game, RIA is as mainstream today as mainstream gets. At the lightweight end of , a number of open-source libraries have caught fire. are ideal for programmers who just need to add a bit of fancy functionality (a date chooser, a data grid, some form preprocessing, etc.) to a page.

[ InfoWorld, with the help of its readers, designs the ideal notebook. .]

A step up from the open-source tools are commercial AJAX frameworks such as Backbase, Bindows, JackBe, and Tibco General Interface. But can these maintain their edge? With so many good open-source alternatives available, why ?

The reasons range from better technical support and documentation to more polish and flexibility. But it's becoming increasingly difficult to draw significant, categorical differences between the open-source and commercial tools.

As the open-source projects extend their reach, the commercial players are finding niches beyond AJAX. For instance, has evolved into an "enterprise mashup" platform that ties together HTML, RSS, Web services, and SQL calls. , plus has and . Laszlo Systems, now the shepherd of , focuses on Web 2.0 desktop solutions for businesses and service providers.