Update: Drupal 7.0 Alpha 4 is available now!
Our second Drupal 7 alpha version was released just over a month ago. Today, we're proud to announce the release of the third alpha version of Drupal 7.x for your further testing and feedback. The first alpha announcement provided a comprehensive list of improvements made since Drupal 6.x, so in this announcement we'll concentrate on how you can help ensure that Drupal 7 is released as soon as possible and is as rock solid as the previous Drupal releases that you've grown to love!
The release notes contain a list of the biggest changes. The most notable change for developers is Drupal 7 now ships with jQuery 1.4 and jQuery UI 1.8. We've also fixed a number of critical issues since the previous alpha, most importantly one that caused passwords to be stored in plain-text under certain conditions. Oops. :P This is a great time to reiterate...
This alpha version should not be used for production sites. We've resolved most errors reported so far, but there are outstanding known issues (including security issues) and most likely some problems that have not been reported as of yet. It is expected that there will be a few beta versions and at least one release candidate before Drupal 7.0 is finalized. You can help us reach the final release date sooner by testing this alpha and providing feedback.
Updating from previous versions
Please note that the upgrade path does not work yet. If you would like to help resolve this, see the list of issues tagged 'D7 upgrade path'. Upgrades will also not be supported between Drupal 7 versions until later in the release cycle, so alpha releases should be installed for testing only.
Always make backups of your data and never do testing on your live site to make sure you keep all of your information intact even if something goes wrong.
So when does 7.0 get released?
The release version of Drupal 7.0 will be ready after (a) there are no more critical bugs and (b) we've had at least one release candidate (RC) without adding any more issues to the list.
When will that be? Well, it depends entirely on how many people chip in and help out! The more people help, the faster we can find and fix bugs, and the faster 7.0 gets released. The faster 7.0 gets released, the faster we can start adding new features to Drupal 8.0. So help out where you can, and let's make this the best and most solid release of Drupal yet! :)
How do I help test the alpha?
Start by either installing a new Drupal site or upgrading an existing one running on a previous version (see INSTALL.txt or UPGRADE.txt in the package). When setting up a new site, you can use the Development module to generate some test data (content, users, etc) to help you start testing quickly. As with everything still in development, we do not recommend running pre-releases on a live site. Also, always make sure to backup of your data before performing an upgrade or start testing.
New Drupal Users
Are you completely (or relatively) new to Drupal? Or do you know just enough to be dangerous? Are you used to working with other content management systems and willing to lend your perspective in improving the way Drupal works? If so, you're a perfect candidate to help with usability testing and improving documentation! As you're going through Drupal 7, take notes on things you find difficult or confusing, and translate those notes into an issue which will show up in the issue tracker. Make sure to be as clear as possible about what the problem was and provide suggestions on how to improve it -- this makes it easier for developers to help!
Do people often congratulate you on your ability to break things? Are you a creative individual who likes to experiment in unconventional ways to see what happens? Do you enjoy looking over other peoples' work and picking nits in order to make it as good as it possibly can be? If any of these apply to you, you could make a great tester! We need testers both to try out different aspects of Drupal itself, as well as take a look at the issue queue, checking bugs to see if they're valid and testing patches to verify they work properly. Read more about setting up a testing environment and applying patches.
Module and theme developers
There is no better way to shake out any lingering bugs with the API and to ensure that your modules and themes will work with the new version of Drupal than to update your modules and update your themes! Make sure to file any bugs that you find!
Drupal Ninjas and Ninjas-in-training
If you're adept at Drupal hacking, or are eager to learn, a great place to start is with the bug tracker or the patch queue. Even if you don't have a full solution for a problem, often even a step in the right direction can be enough for another developer to take it home! Read up on how to create patches.
Drupal interface translators
The interface strings of Drupal 7.0 are mostly frozen. The days of major changes to the UI strings are over, but we still are changing texts to fix bugs or to lend clarity in the interface. Around release candidate 1, a formal "string freeze" will be declared at which point it should be safe to start translating.