Google just announced that Tasks will be the first feature to graduate from Gmail Labs to become a default feature for all Gmail users.

Gmail Labs, which launched about a year ago, holds a collection of experimental additions to Gmail that users can try out by enabling them within their Gmail's settings. It also provides an interesting window into Google's application development philosophy.

Tasks provides a to-do list within Gmail optimized for mobile access and integration with Google Calendar. Senior product manager Keith Coleman says that the decision to add it to the main product was partly based on how many users had signed up to try it and how many have continued to use it. Coleman adds that a handful of other Labs experiments will likely graduate in the near future.

At first, Google wasn't sure if Labs would be a viable way to test features for Gmail, Coleman says, in part due to the technical complications that it introduces. You see, the system generates a different JavaScript codebase for each Gmail user based on which Labs products she has enabled. Since Gmail launched 51 Labs experiments in the past year, there are an astronomical number of possible Gmail builds--far too many to test internally.

But Google considers the experiment a success--so much that the company expanded the system by introducing Google Calendar Labs today. Calendar Labs will offer experimental features such as a time-zone gadget and the ability to track whether friends are free or busy.

Since Google has dropped the famous "beta" tag from many of its applications, Labs gives the company a way to keep the product evolving without disrupting customers who depend on it for business reasons, says Ken Norton, senior product manager for Google Calendar.

While Gmail Labs is known for some quirky widgets, like Mail Goggles (jokingly designed to stop embarrassing late-night e-mails), it also supports efforts to appeal to business customers. Calendar Labs will permit third-party developers to make their own adjustments to Calendar, allowing businesses to make necessary customizations, Norton says. This feature is only designed for use within a particular company: there's no way to make these outside features publicly available. A similar trick is possible in Gmail Labs, Coleman says.

Last weekend, Mozilla evangelist Christopher Blizzard showed off some of the features that will appear in the next version of Firefox at the Southern California Linux Expo.

Firefox 3.1 takes several important steps toward beefing up the browser's ability to run Web applications, one of which is that it adds support for "worker threads." These allow the browser to deal with heavier computation--if it needs to do something data-intensive, JavaScript can run in the background, while the user goes on interacting with the application as normal. This capability is very important for sophisticated Web applications and, in an impressive Firefox 3.1 demo, Blizzard showed off a browser application capable of detecting motion in a live video as it played (see the clip below). Without worker threads, there's no way that the application could have handled this without locking up.

Maybe you're not planning to run a browser application that parses the feed from your security camera? A less flashy but equally important example of the concept can be seen in the new Offline capability from Gmail Labs. Using offline mode, users can access Gmail online or off (or in "flaky connection mode," which smooths out the experience of a now-you-see-it-now-you-don't Internet connection, or a four-hour Gmail outage). One key part of the underlying technology is WorkerPool, which, like Firefox's worker threads, allows intense computation to go on in the background while the user interacts with the Gmail interface. In a conversation I had recently with Gmail product manager Todd Jackson, he explained to me that WorkerPool is what allows Gmail to perform the heavy task of coordinating the data in a user's online Gmail account with what's stored offline, without forcing the user to wait for long periods while the browser responds.

These changes are just part of a larger trend of re-engineering browsers to improve their ability to handle Web applications. Google's Chrome browser is one example of this, as is work on the W3C's HTML 5 specification, which is making great strides in standards for Web applications.

Gmail users will soon no longer need an Internet connection to access their in-boxes and write and send messages. Within the next few days, in an ongoing push to bring cloud computing to the masses, Google will introduce a new experimental feature in Gmail Labs called Offline Gmail. This feature synchronizes e-mail from a user's computer with Google's servers when she's online, and still provides the look and feel of Gmail when she's offline. It relies on Gears, a downloadable piece of software that synchronizes and caches data for Web applications like Google Docs and Calendar.

From Google's blog post:

Once you turn on this feature, Gmail uses Gears to download a local cache of your mail. As long as you're connected to the network, that cache is synchronized with Gmail's servers. When you lose your connection, Gmail automatically switches to offline mode, and uses the data stored on your computer's hard drive instead of the information sent across the network. You can read messages, star and label them, and do all of the things you're used to doing while reading your webmail online. Any messages you send while offline will be placed in your outbox and automatically sent the next time Gmail detects a connection. And if you're on an unreliable or slow connection (like when you're "borrowing" your neighbor's wireless), you can choose to use "flaky connection mode," which is somewhere in between: it uses the local cache as if you were disconnected, but still synchronizes your mail with the server in the background. Our goal is to provide nearly the same browser-based Gmail experience whether you're using the data cached on your computer or talking directly to the server.

According to the post, Google employees have been using the feature for quite some time, which isn't surprising, as most new features get test-driven by Googlers long before they are released to a wider audience. For a glimpse at the future of computing, it's helpful to look at the habits of Google employees.

Of course, the cloud-computing push isn't unique to Google. Adobe offers AIR, a platform to turn Web applications into software that feels as if it's running on a computer's hard drive. And Microsoft, for its part, is trying to make an operating system that plays well with the cloud.