Microsoft has announced a surprise availability of Internet Explorer 8 Beta 1 [release notes] for public download featuring new features such as Automatic Crash Recovery, Activities and WebSlices. Once you upgrade from IE7 to IE8, if you come across an incompatible webpage, you can click the “Emulate IE7″ button in the command bar to browse the site like you did in Internet Explorer 7.

Here is an overview of the new features in Microsoft Internet Explorer 8 beta:

Activities:
Activities are contextual services to quickly access a service from any webpage. Users typically copy and paste from one webpage to another. Activities typically involve two types of scenarios: “look up” information within a webpage or “send” web content to a web application. Users can install Activity Providers from the Internet Explorer 8 Service Guide or through any website that advertises Activities.

WebSlices:
WebSlices is a new feature for websites to connect to their users by subscribing to content directly within a webpage. WebSlices behave just like feeds where clients can subscribe to get updates and notify the user of changes. Internet Explorer 8 subscribes to the webpage, detects changes in the WebSlice, and notifies the user of updates. Users can preview these updates directly from the Favorites bar and click-through to the website to get more information.

Favorites Bar:
In Internet Explorer 7, the Links bar provided users with one-click access to their favorite sites. The Links bar has undergone a complete makeover for Internet Explorer 8. It has been renamed the Favorites bar to enable users to associate this bar as a place to put and easily access all their favorite web content such as links, feeds, WebSlices and even Word, Excel and PowerPoint documents.

Automatic Crash Recovery:
Automatic Crash Recovery (ACR) is a feature of Windows®Internet Explorer® 8 that can help to prevent the loss of work and productivity in the unlikely event of the browser crashing or hanging. The ACR feature takes advantage of the Loosely-Coupled Internet Explorer feature to provide new crash recovery capabilities, such as tab recovery, which will minimize interruptions to users’ browsing sessions.

Improved Phishing Filter:
The Safety Filter continues to block known Phishing sites and now blocks sites known to contain malicious software that could harm users’ computer or steal their information. Beyond this improved protection, the Safety Filter operates more quickly than ever before to ensure that users can browse both safely and quickly.

Internet Explorer 8 Beta is available for download for Windows XP, Vista, 2003 and 2008 Longhorn