trends, people, incurrents the news [ projects Features Editor: Dale Strok ■ [email protected] The Google Web Toolkit Shines a Light on Ajax Frameworks Greg Goth he Google Web Toolkit’s public debut conference, and within hours some developers and rapid maturing have brought atten- became true believers, while others took a tion to the myriad tools and frame- more cautionary view of its Java-to-JavaScript works for facilitating Web applications, paradigm. The fact that it came from Google, particularly those written with Ajax— however, almost guaranteed close industry- T Asynchronous JavaScript and XML (for wide examination and the subsequent spec- more on Ajax, see the sidebar). One Ajax tech- trum of opinion. nology veteran, Charles Kendrick, says GWT’s “Everything Google releases gets a lot of debut had significance for the industry far be- scrutiny,” says Bret Taylor, senior product yond Google itself. manager for Google’s developer group. “We “I think it was a lot like what Google Maps love the feedback even if it’s a little feisty at did for Ajax technology in general,” says times. But I think really what I see is a lot of Kendrick, chief architect of Isomorphic Soft- language warfare. Because it’s a Java-centric ware, which develops the commercial Smart- product right now, folks who aren’t big Java Client Ajax framework. “It legitimized the fans are probably not big GWT fans either. All idea of an Ajax component framework and these toolkits offer a lot of value, and it really made Ajax frameworks more visible. Google comes down to the programming environment was out there saying, ‘You don’t want to roll and languages you’re most familiar with.” your own.’” Taylor’s observations perhaps illustrate the Kendrick isn’t alone in asserting that difficulty of empirically evaluating GWT and GWT’s debut signals a new era of visibility for other Ajax frameworks side-by-side. Their ca- Ajax frameworks. Joshua Gertzen, lead devel- pabilities are similar enough that they seem to oper for ThinWire (www.thinwire.com), an be aiming toward the same end point—dynamic open source Ajax framework, says GWT’s re- Web applications that are more easily devel- lease is a continuation of the Ajax trajectory oped. Those same capabilities are also divergent Google followed with the creation of Google enough that getting a handle on what frame- Maps and Google Mail. work works best for which programming task “Something like GWT does have its merits, is sometimes confusing. Rather than a clear-cut and I think Google is to be credited with bring- comparison of apples and oranges, Ajax devel- ing widespread Ajax adoption to the fore- opers face the subtleties of comparing what front,” Gertzen says. “There’s no question that Kendrick concurs to be “apples and a different Google Maps and Google Mail played a large kind of apples.” part in that, a lot more so than the coining of ThinWire’s Gertzen says you can roughly the term Ajax itself.” separate the current Ajax market into “two distinct groups—the public-facing applications New tool from deep pockets and the business, enterprise-class applications. GWT (http://code.google.com/webtoolkit) The public-facing applications have really got- debuted at the May 2006 JavaOne developers’ ten most of the limelight.” 94 IEEE SOFTWARE Published by the IEEE Computer Society 0740-7459/07/$25.00 © 2007 IEEE CURRENTS What could confuse developers trying to evaluate GWT’s suitability, Gertzen The Google Web Toolkit: Big Pea in the Ajax Pod says, is the seeming incompatibility be- tween its development environment— GWT might be the most visible manifestation of the Ajax framework, herald- pure Java, far more popular for server- ing more widespread use of the popular dynamic development model. side development than for Web The term Ajax, for Asynchronous JavaScript and XML, was coined in 2005 applications—and its stated goal of help- by Jesse James Garrett, president of Adaptive Path, a technology strategy and ing developers more easily write Web ap- design firm. Ajax development adds a layer of software in the traditional Web plications with Java. interface. But rather than slow down data retrieval, Ajax speeds it up by letting “GWT is interesting to me because the application load only the updated elements of the desired Web page. it kind of wants to be enterprise, but it Ajax, as its name implies, isn’t a single technology but rather a group of kind of doesn’t,” Gertzen says. “GWT technologies that deliver a desired action. Its components include XHTML and is using Java, trying to make it seem CSS (cascading style sheets) for presentation, the Document Object Model for like it’s a structured environment, but display and interaction, asynchronous data retrieval via XMLHttpRequest, inter- they also seem to be saying ‘We have change via XML and XSLT (Extensible Style Sheet Language Transformation), and no real significant components, we JavaScript. haven’t thought through about what’s The performance premium that Web developers (and users) obtain with Ajax needed to build more data-centric, has been its main attraction. However, the intricacies of JavaScript development data-input types of applications instead on the most popular browsers have caused many headaches; subtle incompati- of Web pages types of applications.’ So bilities from browser to browser delay application deployment. So, Google touts I think there’s still a little bit of room in GWT as offering developers both the ability to compile Java code to JavaScript terms of how things will pan out, but and browser-to-browser compatibility. just the fact it has such a huge name “The reason we released GWT was to improve the number and quality of behind it means it will be a key player.” Ajax applications,” says Google product manager Bret Taylor. “We run a fairly Isomorphic’s Kendrick, too, says large search engine here and think what’s good for the Web is good for Goo- GWT’s emphasis on Java seems incon- gle. So we released it to give developers access to some of the knowledge and gruous considering the toolkit’s likely experience we’ve developed with Ajax.” environment. GWT is just one of dozens of open source and commercial Ajax frameworks. “When we are in licensing discussions Its importance might increase now that it has become an open source project with ISVs [independent software ven- under the Apache 2.0 license. Already, developers are praising its ability to let dors], other frameworks such as Tibco or them develop Web applications in tandem with tools from the open source Eclipse Backbase will come up, but never GWT platform. With additional third-party tools and widgets being developed espe- to date,” he says. “ISVs haven’t shown cially for GWT, its impact bears watching. much interest in it. To me, it’s something that appeals to somebody who is already an expert Java developer and knows a lot of Java tools, which isn’t your typical almost like going a little backwards,” the things he’s most proud of are the Ajax developer. A lot of Ajax develop- Taylor says. “But the reason we re- Java-to-JavaScript compiler and the ers like PHP or come from a Web- leased it is, when you’re developing a amount of work Google developers programming background. I think it ap- really large product like Gmail or have put into eliminating the idiosyn- peals to those who see the necessity of Google Maps and have a large devel- cratic behavior that identical code of- Ajax for their applications but are a bit opment team, things like having types ten exhibited on different platforms be- terrified of the browsers and JavaScript in your language, and well-defined in- fore GWT’s release. and that stuff, and GWT lets them stay terfaces, and modularity matter a lot “There were a lot of people in Sili- on their home turf.” more. In projects like this, you need to con Valley who maybe were really fa- Google’s Taylor says the increasing share code, automatically generate in- miliar with the idiosyncrasies of Java- complexity of Web-based application formation about interfaces, and use Script in browsers who felt very development will mandate that pro- code completion and things like that, comfortable doing Ajax,” Taylor says. gramming teams adopt a hybrid lan- that are virtually impossible with lan- “And, I think there’s also a class of guage approach—one that GWT is guages like JavaScript.” professional developers who are famil- well suited to fill. iar with languages like Java and were a “For people who are very familiar So who wants to play with it? little intimidated by the prospect of hav- with scripting languages, the prospect In the short time that developers ing to understand the idiosyncrasies of of going from a dynamic scripting lan- outside Google have been using GWT, four different browsers and three differ- guage to a more strictly typed tradi- it has garnered kudos for several of its ent operating systems. So it’s been pop- tional language like Java might seem technical hallmarks. Taylor says two of ular with that group, which didn’t want March/April 2007 IEEE SOFTWARE 95 CURRENTS IBM and Universities in Open Source Collaboration Terry Costlow ndustry-academia collaborations and basic research often velopment for the open source movement. IBM’s move “recog- get hung up by legal wrangling, but open source soft- nizes open source as a legitimate licensing regime,” says I ware’s burgeoning popularity might break down some Michael Tiemann, a pioneer in the open source movement walls.