Currently there are three implementations of the .NET framework:

1. Microsoft .NET
2. Mono
3. Portable.NET

The .NET platform uses a platform neutral intermediate language (IL), which means that programs built with one implementation should run on all the others. In practice there are some areas which are specific to each of the .NET implementations, however with care it is possible to build cross-platform programs.

To run .NET programs a runtime environment is required. To develop .NET programs an appropriate development environment is needed.

To run .NET executables on Microsft Windows the Microsoft .NET Framework must be installed. On Windows Vista and Windows 7 the .NET Framework is installed by default. For Windows XP the .NET Framework is available as an optional update from Windows Update, or Microsoft Update, or can be downloaded from http://www.microsoft.com/net/Download.aspx.

The Mono Project provides a run-time and development environment for many operating system platforms. The Mono run-time environment for your platform may be available via your system's package manager or from the Mono Project web site.

The Microsoft .NET SDK is available as a free download from the MSDN site.

This installs the required framework components and the development tools. The SDK provides all the command-line tools necessary for .NET development. Use the “SDK Command Prompt” to access the programs in the SDK.

The SDK includes development tools for:

• C#
• Visual Basic .NET

If you require an editor or IDE for development with the SDK, you may find the following of interest:

• SharpDevelop
• Emonic plug-in for Eclipse
• C# modes for Emacs

Note: If you have a full version of Microsoft Visual Studio installed the .NET SDK is included as part of the package.

Mono is an open source implementation of the .NET framework, which includes the development tools. The main advantage of Mono over the Microsoft .NET SDK is a wider range of platform support including MS Windows, Linux and MacOS X. Like the Microsoft .NET SDK Mono only provides the command-line development tools. However an IDE is available from the associated MonoDevelop project.

If you are using a package based Linux system (e.g. Ubuntu) check the list of available packages for a pre-packaged version of Mono. If your system is not package based or a Mono package is not available see the Mono website for details of how to download and install Mono.

The Microsoft Visual Studio Express products provide the main features of the Microsoft Visual Studio development platform in single language packages. These are freely available from the Microsoft Visual Studio Express website.

Note: these products do not include the Microsoft .NET SDK, but instead use an integrated version of the tools available only via the IDE. If you want to use a Microsoft Visual Studio Express product in conjunction with the Microsoft .NET SDK you will have to install the SDK separately.

The flagship of Microsoft's developer products Visual Studio provide multiple language support and advanced development features.

Support for web services is a core feature of .NET and thus is available in all .NET programming languages. Currently .NET features two frameworks for accessing web services:

1. System.Web.Services
   Available in all versions of Microsoft .NET and Mono. Generated service code stubs are known as “Web References”. Supports most SOAP services, including the RPC/encoded SOAP style.
2. Windows Communication Foundation (WCF)
   Available in Microsoft .NET from version 3.0, and some support in Mono (see WCF Development). Generated service code stubs are known as “Service References”. Does not support RPC/encoded style SOAP services (see Interoperability Gotcha: Visual Studio 2008 Proxy Flavours).

.NET Bio, the successor Microsoft Biology Foundation (MBF), provides a bioinformatics tool-kit for the .NET platform and includes integrations of a number of bioinformatics Web Services, for example:

The .NET platform supports a wide range of programming languages (see Language List). To get you started using .NET with the EMBL-EBI Web Services we have tutorials for the two most commonly used .NET languages:

• C#
• Visual Basic .NET