DotNET Version

Changes in 1.1 on comparison with 1.0

* Built-in support for mobile ASP.NET controls. Previously available as an add-on for .NET Framework, now part of the framework.
* Security changes - enable Windows Forms assemblies to execute in a semi-trusted manner from the Internet, and enable Code Access Security in ASP.NET applications.
* Built-in support for ODBC and Oracle databases. Previously available as an add-on for .NET Framework 1.0, now part of the framework.
* .NET Compact Framework - a version of the .NET Framework for small devices.
* Internet Protocol version 6 (IPv6) support.
* Numerous API changes.

Changes in 2.0 in comparison with 1.1

* Numerous API changes.
* A new hosting API for native applications wishing to host an instance of the .NET runtime. The new API gives a fine grain control on the behavior of the runtime with regards to multithreading, memory allocation, assembly loading and more (detailed reference). It was initially developed to efficiently host the runtime in Microsoft SQL Server, which implements its own scheduler and memory manager.
* Full 64-bit support for both the x64 and the IA64 hardware platforms.
* Language support for generics built directly into the .NET CLR.
* Many additional and improved ASP.NET web controls.
* New data controls with declarative data binding.
* New personalization features for ASP.NET, such as support for themes, skins and webparts.
* .NET Micro Framework - a version of the .NET Framework related to the Smart Personal Objects Technology initiative.
* Partial classes
* Anonymous methods
* Data Tables

Changes since version 3.0

* New language features in C# 3.0 and VB.NET 9.0 compiler
* Adds support for expression trees and lambda methods
* Extension methods
* Expression trees to represent high-level source code at runtime.
* Anonymous types with static type inference
* Language Integrated Query (LINQ) along with its various providers
o LINQ to Objects
o LINQ to XML
o LINQ to SQL
* Paging support for ADO.NET
* ADO.NET synchronization API to synchronize local caches and server side datastores
* Asynchronous network I/O API.
* Peer-to-peer networking stack, including a managed PNRP resolver
* Managed wrappers for Windows Management Instrumentation and Active Directory APIs[25]
* Enhanced WCF and WF runtimes, which let WCF work with POX and JSON data, and also expose WF workflows as WCF services. WCF services can be made stateful using the WF persistence model.
* Support for HTTP pipelining and syndication feeds.
* ASP.NET AJAX is included
* New System.CodeDom namespace.