Another approach is to employ tools that use declarative markup (in the form of tags) to generate JavaScript. Enterprise developers, who are often starting from a Java-based or .NET-based Web application stack, may already have ready-to-run tag libraries available to AJAX-enable their pages. ASP.Net AJAX8 as well as JSF (JavaServer Faces) Dynamic Faces9 are just two examples of libraries that allow declarative markup to generate AJAX capabilities in a Web page.

This approach is not as flexible as some other ways to create JavaScript; however, it is a quick, easy way to add some AJAX functionality within a technology stack that is already adopted at your firm.

Targeting Browser Plug-Ins: Bring Your Own Language
While browser plug-in applications can have their own issues (vendor control, slow startup time, less-than-100% install base), they represent the most direct route for enterprise RIA deployment without building a JavaScript application.

Nearly all of the widely used Web app development languages are present in plug-ins today, and more are coming: the Java plug-in can, of course, run Java applications, but it can also run JavaFX scripts, Python (via Jython), and even Ruby (via JRuby)¹⁰. Silverlight 1.0 requires JavaScript, but the upcoming 1.1 release of this Microsoft plug-in adds support for .NET languages such as C#, Python (IronPython), Ruby (IronRuby), Visual Basic, and others¹¹.

Flash Player versions 9 and up support ActionScript 3. ActionScript 3, while less familiar to enterprise coders than C# or Java, is an implementation of ECMAScript 4¹². As such, it brings classes, static typing, packages, namespaces, and other familiar elements that make an easy on-ramp for C# or Java developers. Adobe's Flex development tool adds another layer of familiarity, since it is built on the Eclipse IDE used by many enterprise developers already¹³.

Though plug-in based RIAs are not strictly AJAX, in many cases they meet or exceed enterprise and customer requirements, while bringing traditional languages and powerful development capabilities such as complete control over graphics and networking operations.

Conclusion
Enterprise development faces challenges that make the transition to AJAX trickier than it is for a startup. Nonetheless, there are a variety of ways to address these challenges.

Solutions range from improvements in development and testing processes, which make it easier to deploy rock-solid apps via script, to mechanisms for avoiding script altogether and using the company's existing technical know-how instead.

As long as we think carefully about the issues - especially how they work at our company - rather than grabbing onto the latest trend for its own sake, we can not only be successful, but also contribute to enterprise best practices for AJAX, which are just beginning to be invented.

Resources/Notes
1.  Kevin Clark's Heckle library: http://glu.ttono.us/articles/2006/12/19/tormenting-your-tests-with-heckle
2.  Douglas Crockford's JSLint: www.jslint.com/lint.html
3.  Subversion version control system: http://subversion.tigris.org/
4.  Eval in Mozilla-based browsers:
http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Guide:Predefined_Functions:eval_Function
  •   In Internet Explorer: http://msdn2.microsoft.com/en-us/library/12k71sw7.aspx
  •   In PHP: http://us2.php.net/eval
  •   In Ruby: www.ruby-doc.org/core/classes/Kernel.html#M005947
  •   In Python: http://docs.python.org/lib/built-in-funcs.html
5.  By concrete proxy, we mean objects with concrete methods or properties, rather than dynamically dispatched calls. Examples of the latter include dynamic proxies built on Ruby's method_missing, ActionScript's flash.utils.Proxy, etc.)
6.  Google Web Toolkit: http://code.google.com/webtoolkit/
7.  Nikhil Kothari's Script#: www.nikhilk.net/ScriptSharpIntro.aspx
8.  ASP.Net AJAX: www.asp.net/ajax/
9.  JSF Dynamic Faces: https://jsf-extensions.dev.java.net/nonav/mvn/gettingstarted-ajax.html
10.  Jython applets: www.jython.org/applets/index.html
  •   JRuby applets are not mainstream-practical today, but will be soon:
http://headius.blogspot.com/2006/11/ruby-for-web-check.html
  •   JavaFX applications are typically deployed as Java Web Start apps (running outside of the browser), but can run in an applet as well:
www.reportmill.com/jfx/gallery/
11.  Microsoft GM Scott Guthrie on Silverlight 1.0 and 1.1 language support: Click Here !
12.  ActionScript 3: www.adobe.com/devnet/actionscript/articles/actionscript3_overview.html
13.  Adobe Flex: www.adobe.com/products/flex/