Google announced today that they’re launching a web browser called Chrome. Their announcement discussed numerous features but the important ones all revolve around making the browser a more stable development platform for web applications.

There are some really good JavaScript web apps out there right now, many written by Google themselves (Gmail, Google Reader, Google Apps). Some of these web apps are very sophisticated and really push the boundaries of what browsers and JavaScript can do. But they’re all hampered by one serious limitation–today’s web browsers are not serious application platforms.

Google sums up the browser problems in an online comic book. Browsers are unstable, too slow, not secure, and inherently single-threaded. Most of the new Rich Internet Application (RIA) technologies use plug-ins designed specifically to bypass these limitations. For example, Microsoft Silverlight is a downloadable library that introduces multi-threading, compiled code (speed), and a secure sandbox.

But now Google is going to address all of these problems at the browser level, in ways that will make the browser act a lot like an operating system. The biggest change is that Chrome will handle processes instead of threads, which is one of the fundamental responsibilities of Windows.

Google is also creating their own JavaScript virtual machine (V8), designed for large programs, giving it many of the features of a strongly typed language. It will have garbage collection (a complicated feature of high-end programming languages) and a secure sandbox. Most important, V8 has a just-in-time JavaScript compilation that generates machine code running directly on the CPU that’s running the browser.

Joel On Software (a great blog by a former Microsoft programmer) lays out an interesting parallel between software twenty years ago and web technology today. The entire article is an amazing read, but here is the relevant part:

Imagine that you’re Google with GMail, and you’re feeling rather smug. But then somebody you’ve never heard of, some bratty Y Combinator startup, maybe, is gaining ridiculous traction selling NewSDK, which combines a great portable programming language that compiles to JavaScript, and even better, a huge Ajaxy library that includes all kinds of clever interop features. Not just cut ‘n’ paste: cool mashup features like synchronization and single-point identity management (so you don’t have to tell Facebook and Twitter what you’re doing, you can just enter it in one place). And you laugh at them, for their NewSDK is a honking 232 megabytes … 232 megabytes! … of JavaScript, and it takes 76 seconds to load a page. And your app, GMail, doesn’t lose any customers.

But then, while you’re sitting on your googlechair in the googleplex sipping googleccinos and feeling smuggy smug smug smug, new versions of the browsers come out that support cached, compiled JavaScript. And suddenly NewSDK is really fast. And Paul Graham gives them another 6000 boxes of instant noodles to eat, so they stay in business another three years perfecting things.

And your programmers are like, jeez louise, GMail is huge, we can’t port GMail to this stupid NewSDK. We’d have to change every line of code. Heck it’d be a complete rewrite; the whole programming model is upside down and recursive and the portable programming language has more parentheses than even Google can buy. The last line of almost every function consists of a string of 3,296 right parentheses. You have to buy a special editor to count them.

And the NewSDK people ship a pretty decent word processor and a pretty decent email app and a killer Facebook/Twitter event publisher that synchronizes with everything, so people start using it.

And while you’re not paying attention, everybody starts writing NewSDK apps, and they’re really good, and suddenly businesses ONLY want NewSDK apps, and all those old-school Plain Ajax apps look pathetic and won’t cut and paste and mash and sync and play drums nicely with one another. And Gmail becomes a legacy. The WordPerfect of Email. And you’ll tell your children how excited you were to get 2GB to store email, and they’ll laugh at you. Their nail polish has more than 2GB.

Crazy story? Substitute “Google Gmail” with “Lotus 1-2-3”. The NewSDK will be the second coming of Microsoft Windows; this is exactly how Lotus lost control of the spreadsheet market. And it’s going to happen again on the web because all the same dynamics and forces are in place. The only thing we don’t know yet are the particulars, but it’ll happen.

That’s what is happening right now, the difference is that instead of Google being the victim, they’re the ones who are enabling NewSDK. Google is not only building the JavaScript compiler, they’re also rebuilding the browser (which fixes 10 other obstacles that Joel doesn’t mention in the article). These are all prerequisites for theoretical JavaScript technologies like NewSDK to really catch on and work correctly for enterprise applications.

Google isn’t trying to own the “Internet operating system” financially, only strategically. But if everything comes together , they will prevent Microsoft, Adobe, or anybody else from creating an RIA/Web 3.0 extension that becomes the new platform for web development. And they’ll still generate a lot of revenue from things like Google Apps that can be packaged and sold to large corporations, as well as work as an advertising platform for individual users.

Chrome is open source, which is important because Google doesn’t even have to get significant penetration with their browser. Other browsers (like FireFox) can swipe all their ideas and code and build them into their own browsers. All Google has to do is make their code work well enough that other companies want to incorporate it.

This is one of the most interesting things to happen in years. At the very least, it will create a lot more possibilities for Java/Open Source developers. And it’s entirely possible that Google will leapfrog Microsoft Windows and the technologies behind Chrome will become the basis for a new Internet operating system.

I personally think that no one company will win these wars. Five years from now, all browsers will have Adobe Flex, Microsoft Silverlight, and Google’s Chrome technology built in, allowing developers to use any combination of platforms to deliver sophisticated web applications.

But not everybody agrees with me:

Expect to see millions of web devices, even desktop web devices, in the coming years that completely strip out the Windows layer and use the browser as the only operating system the user needs. That was going to happen anyway, but Chrome + Gears just made the decision a whole lot easier for hardware manufacturers to make.

Microsoft, meanwhile, is stuck with a bloated closed source browser that they don’t even tether to their search engine for fear of more antitrust woes. Google can push their search engine and other web services all day long on Chrome, with no government interference. So not only will Chrome drive lots of incremental revenue to Google, it also paves the way for a Microsoft-free computing experience.

We’re in the middle of the new operating system war.