Earlier today the ASP.NET team shipped the release candidate for ASP.NET AJAX 1.0. This is the penultimate release of ASP.NET AJAX - the next public release will be the final, fully supported, 1.0 product.

This release candidate build includes several new features, and one important change, from the Beta2 release. You can read a document that lists all changes from the CTP->Beta1->Beta2->RC here. At a high-level, the changes from Beta2 to RC include:

- Inclusion of a built-in VS 2005 Web Application Project template to create new ASP.NET AJAX applications. This now allows you to pick File->New Project (in addition to the existing template in File->New Web Site) to create new ASP.NET AJAX enabled web applications. - Additional globalization support for AJAX applications, as well as additional script resource handler features to improve substitution logic, compression and caching. Dynamic invocation of web service proxies from JavaScript is also now supported. - The assembly name of ASP.NET AJAX changed from Microsoft.Web.Extensions.dll to System.Web.Extensions.dll, and the namespace of the server-side features of ASP.NET AJAX changed from Microsoft.Web to System.Web. Note that the client JavaScript namespaces did not change (which avoids breaking existing client JavaScript code).

The team made this last server namespace and assembly change for two reasons:

1) Because ASP.NET AJAX will be a fully-supported part of the core .NET Framework going forward, and so for consistency it makes sense for the final release to live under the "System" namespace - which is where the other core parts of the .NET Framework and ASP.NET live.

2) Because it will help make upgrading to the "Orcas" release of ASP.NET and Visual Studio much easier. ASP.NET AJAX will be built-in with "Orcas" (so you don't have to download and install it separately), and by making the namespace change it means that your code will not need to change. You'll be able to optionally keep your applications running using the ASP.NET AJAX 1.0 release just fine if you want (it will run and be supported on top of Orcas) - or you'll be able to change the version string in your web.config file and automatically upgrade to the newer version of ASP.NET AJAX that will be included built-in to ASP.NET "Orcas".

This whitepaper provides step-by-step instructions on how to upgrade existing ASP.NET AJAX Beta2 applications to the ASP.NET AJAX RC build.

Important Intellisense Tip:

One additional step you'll want to make after you follow the steps in the whitepaper above is to delete the cached schema files for control markup Intellisense that VS maintains. This will ensure that your HTML source editor Intellisense for the ASP.NET AJAX controls is correct and doesn't get lost (otherwise it might incorrectly use the old values from the Beta2 release).

- With Windows XP you do this by deleting all files in this directory: c:\Document and Settings\[YourUserName]\Application Data\Microsoft\VisualStudio\8.0\ReflectedSchemas - With Windows Vista you do this by deleting all files in this directory: c:\Users\[YourUserName]\AppData\Roaming\Microsoft\VisualStudio\8.0\ReflectedSchemas

Once you delete these schema files and restart VS, it will re-calculate the HTML markup Intellisense for all controls and pick up the changes from the assembly name change.

Hope this helps,

Scott