They're back! Just when you thought the "browser wars" were over, with the two camps -- Microsoft and Mozilla.org -- settling in for a kind of intransigent détente, along comes Google to stir things up all over again. Clearly Google is unhappy with the current state of browser geopolitics and feels it needs to roll its own in order to ensure a robust base for its myriad hosted applications (e.g. Gmail, Google Docs, etc.)

To that end, Google has designed an almost completely new Web browser. In fact, other than the core rendering engine -- which is based on the open-source WebKit standard of Safari fame -- everything in Google Chrome constitutes a rethinking of how you engineer a browser application. For example, with the current versions of Mozilla Firefox and Internet Explorer, individual Web page tabs are hosted in a single process -- a model that is efficient (in terms of memory and resource consumption) but also prone to catastrophic failures: A single crashed tab can easily take down the entire browser application.

Chrome seeks to eliminate this problem by isolating each tab within its own application process and then leveraging the built in memory protection capabilities of modern, preemptively multitasking operating systems to keep code and data in a failing tab from stomping on other processes. So now, when that buggy Flash applet on your favorite humor site goes belly up, it won't necessarily take down the entire browser -- the processes running in other tabs will keep chugging along.

This is a big deal for Google, which is banking on wider adoption of its hosted application offerings and battling the perception that browsers are unreliable, especially when you start running multiple Web applications in a tabbed format. Nobody wants to trust their line-of-business applications to an unstable environment, so Google hopes that Chrome will provide the kind of robustness that can assuage customers' fears.

Double stuff browsers

Of course, few technology ideas are truly original, and the case of the multi-process, tabbed browser is no exception. In fact, Google can't even claim to be the first to market with this model -- Microsoft beat them to the punch by a week when it released its own take on multi-process browsing in the form of Internet Explorer 8 Beta 2.

Like Chrome, IE 8 uses multiple, discrete processes to isolate and protect each tab's contents. However, while Chrome takes a purist approach and literally launches a new process with each opened tab, IE 8 uses more of a hybrid model: It creates multiple instances of the iexplore.exe process but doesn't specifically assign each tab to its own instance. Thus a look at Task Manager under Windows will show an equal or greater number of Chrome instances than running tabs, whereas IE 8 will generate a fewer number of instances -- for example, six copies of iexplore.exe to support 10 discrete tabs -- and share them among the running tabs.