What is new in Dot.Net 3.5

1. ASP.NET AJAX
1. In ASP.NET 2.0, ASP.NET AJAX was used as an extension to it. You had to download the extensions and install it. However in ASP.NET 3.5, ASP.NET AJAX is integrated into the .NET Framework, thereby making the process of building cool user interfaces easier and intuitive.
2. JSON Support
1. It is also worth noting that Windows Communication Foundation (WCF) now supports JSON along with other standard protocols like SOAP, RSS and POX.
3. New Controls
1. The ListView and DataPager are new controls added along with a new datasource control called the LinqDataSource.
4. LINQ
1. LINQ (Language Integrated Query) adds native data querying capability to C# and VB.NET along with the compiler and Intellisense support. LINQ is a component of .NET 3.5. LINQ defines operators that allow you to code your query in a consistent manner over databases, objects and XML. The ASP.NET LinqDataSource control allows you to use LINQ to filter, order and group data before binding to the List controls.
5. ASP.NET Merge Tool
1. ASP.NET 3.5 includes a new merge tool (aspnet_merge.exe). This tool lets you combine and manage assemblies created by aspnet_compiler.exe. This tool was available earlier as an add-on.
6. New Assemblies
1. The new assemblies that would be of use to ASP.NET 3.5 developers are as follows: 
1. System.Core.dll - Includes the implementation for LINQ to Objects
2. System.Data.Linq.dll - Includes the implementation for LINQ to SQL
3. System.Xml.Linq.dll - Includes the implementation for LINQ to XML
4. System.Data.DataSetExtensions.dll - Includes the implementation for LINQ to DataSet
5. System.Web.Extensions.dll: Includes the implementation for ASP.NET AJAX (new enhancements added) and new web controls as explained earlier.
7. Enhanced Side By Side Support
1. ASP.NET 3.5 provides better support to IIS7. IIS7 and ASP.NET 3.5 modules and handlers support unified configuration.
2. You can have multiple versions of ASP.NET on the same machine.
3. For those who are wondering what happened to ASP.NET 3.0, well there isn’t anything called ASP.NET 3.0.
4. VS 2002 worked with ASP.NET 1.0, VS 2003 worked with ASP.NET 1.1, and VS 2005 worked with ASP.NET 2.0. However VS 2008 supports multi-targeting, i.e it works with ASP.NET 2.0, and ASP.NET 3.5.