Web 2.0 and AJAX: What It Means for Enterprise Web Application Development

ByVRISols

The term Web 2.0 has been on every architect’s slide deck for about a year now, since O’Reilly’s article popularized it. For application architects inside enterprises, the marketing definition is no longer the interesting question. The question is whether any of this should change how internal CRM, HR portals, and customer-facing applications get built going forward.

The short answer is yes, but selectively.

Defining Web 2.0 beyond the buzzword

Strip away the marketing layer and three concrete things are happening:

  1. User-generated content. Sites built around contributions rather than editorial publishing. Wikipedia, Flickr, blog platforms. Inside enterprises this maps to wikis, internal knowledge bases, and product review functionality.
  2. Rich Internet Applications. Browser-based software that behaves like desktop applications. Inline editing, drag and drop, partial page updates, immediate feedback.
  3. Mashups. Applications that combine data and services from multiple sources through public APIs. The classic example is plotting listings on Google Maps.

For enterprise architects, the second strand matters most. RIAs change the equation between thin and thick clients in ways that have been promised for a decade and are only now technically real.

AJAX in five minutes

AJAX, Asynchronous JavaScript and XML, is the technique that makes most current RIAs possible inside the browser. The mechanics are simple:

  1. The browser issues an HTTP request in the background using the XMLHttpRequest object.
  2. The server responds with data, increasingly JSON rather than XML.
  3. JavaScript updates a portion of the DOM without a full page reload.

Two products turned this into a standard user expectation. Gmail proved that a full email client running in a browser could feel responsive. Google Maps showed that a viewport could be panned and zoomed without a single page refresh. Neither was buildable with traditional postback architectures.

Where AJAX changes the user experience inside enterprises

The question is not whether AJAX is technically possible. It is where the payoff justifies the engineering cost. We see four clear wins:

  1. Form-heavy applications. Inline validation, dependent dropdowns, and autocomplete. Insurance quoting, order entry, and HR onboarding screens are obvious candidates.
  2. Search and filtering. Faceted navigation that refines results without reloading the page.
  3. Dashboards and reports. Drill-down without losing context. Sortable, resizable grids without postbacks.
  4. Workflow approvals. Inline comments and status updates rather than constant list-to-detail navigation.

For brochureware and content sites, AJAX adds cost without proportional benefit. Use it where the interaction model actually demands it.

Tradeoffs you cannot ignore

  1. Browser compatibility. Internet Explorer 6 is still dominant in most enterprises. IE7 ships next month. Firefox 1.5 is widespread and 2.0 is imminent. XMLHttpRequest is implemented inconsistently across them. Every project needs a documented browser support matrix.
  2. The back button. Single-page interfaces break browser history by default. Users press back and land on the previous site. Workarounds using URL fragments exist but require deliberate engineering.
  3. Search engine visibility. Content loaded by JavaScript is largely invisible to crawlers. For customer-facing applications that need SEO, plan a server-rendered fallback or accept the cost.
  4. Accessibility. Screen readers struggle with content that updates without page navigation. WAI-ARIA is being discussed but is not yet stable. Public sector and regulated industry projects need to take this seriously.
  5. Debugging and testing. State now lives in the client. Bugs are harder to reproduce. Existing test automation tools need extension.

Libraries worth watching

Hand-rolled XMLHttpRequest is no longer the right starting point. Three options matter today:

  1. Prototype. The most widely deployed JavaScript library. Cross-browser AJAX, DOM utilities, class-based object orientation. Used by Apple, NASA, and many enterprise vendors.
  2. script.aculo.us. Built on top of Prototype. Visual effects, drag and drop, autocompletion. The two are typically adopted together.
  3. jQuery. Released v1.0 last month. The selector-based API is more concise than Prototype, and the cross-browser handling is cleaner. Too early to recommend for production-critical work, but worth piloting on a small project this quarter.

Microsoft’s ASP.NET AJAX, previously codenamed Atlas, is still in beta. DWR remains the practical choice for Java shops needing direct server-side integration.

What this means for offshore development teams

For ODCs serving ISVs and enterprise clients, three implications follow:

  1. Skills shift. JavaScript is no longer the junior developer’s territory. Senior engineers need real proficiency in the language, including closures, prototype-based inheritance, and the DOM event model.
  2. A formal browser test matrix. IE6, IE7, Firefox 1.5, Firefox 2.0 at minimum. Safari if the customer base warrants. This needs dedicated hardware or virtual machines per browser version, plus test scripts that exercise every supported configuration.
  3. Front-end specialization. The era of the full-stack developer who handles JSP templates plus a bit of JavaScript is ending for RIA projects. Expect to staff dedicated front-end engineers within twelve months.

Closing thought

Web 2.0 is mostly a label. AJAX is not. The technique is mature enough for production today, and the productivity gains for the right class of application are real. The discipline is choosing where the engineering investment pays back, and accepting the testing, accessibility, and compatibility burden that comes with it.