Version 4 (V4) of the AWS SDK for .NET has been released\!

For information about breaking changes and migrating your applications, see the [migration topic](https://docs.aws.amazon.com/sdk-for-net/v4/developer-guide/net-dg-v4.html).

 [https://docs.aws.amazon.com/sdk-for-net/v4/developer-guide/net-dg-v4.html](https://docs.aws.amazon.com/sdk-for-net/v4/developer-guide/net-dg-v4.html)

# What is the AWS SDK for .NET
<a name="welcome"></a>

The AWS SDK for .NET makes it easier to build .NET applications that tap into cost-effective, scalable, and reliable AWS services such as Amazon Simple Storage Service (Amazon S3) and Amazon Elastic Compute Cloud (Amazon EC2). The SDK simplifies the use of AWS services by providing a set of libraries that are consistent and familiar for .NET developers..

![Overview of the AWS SDK for .NET](http://docs.aws.amazon.com/sdk-for-net/v4/developer-guide/images/overview.png)


(**OK, got it\!** I'm ready to [set up](net-dg-config.md) and [take a quick tour](quick-start.md).)

## About this version
<a name="about-this-version"></a>

**Current and past documentation**  
This documentation is for version 4.0 and later (V4) of the AWS SDK for .NET. It's mostly centered around .NET Core and ASP.NET Core, but also contains information about .NET Framework and ASP.NET 4.*x*. In addition to Windows and Visual Studio, it gives equal consideration to cross-platform development.  
For information about migrating from earlier versions of the SDK, see [Migrating your project](net-dg-migrating.md).  
For information about the previous version of the SDK, V3, which will be deprecated in the future, see the [AWS SDK for .NET (V3) Developer Guide](https://docs.aws.amazon.com/sdk-for-net/v3/developer-guide/).  
To find deprecated content for earlier versions of the SDK, see the following item(s):  
[AWS SDK for .NET (version 2, deprecated) Developer Guide](samples/aws-sdk-net-v2-dg__deprecated-content.zip)
[Deprecated API references for the AWS SDK for .NET](sdk-api-ref.md#about-api-versions)

## Maintenance and support for SDK major versions
<a name="sdks-major-versions-maintenance-support"></a>

For information about maintenance and support for SDK major versions and their underlying dependencies, see the following in the [AWS SDKs and Tools Reference Guide](https://docs.aws.amazon.com/sdkref/latest/guide/overview.html):
+ [AWS SDKs and tools maintenance policy](https://docs.aws.amazon.com/sdkref/latest/guide/maint-policy.html)
+ [AWS SDKs and tools version support matrix](https://docs.aws.amazon.com/sdkref/latest/guide/version-support-matrix.html)

## Common use cases
<a name="common-use-cases"></a>

The AWS SDK for .NET helps you realize several compelling use cases, including the following:
+ Manage users and roles with [AWS Identity and Access Management (IAM)](https://docs.aws.amazon.com/IAM/latest/UserGuide/).
+ Access [Amazon Simple Storage Service (Amazon S3)](https://docs.aws.amazon.com/AmazonS3/latest/userguide/) to create buckets and store objects.
+ Manage [Amazon Simple Notification Service (Amazon SNS)](https://docs.aws.amazon.com/sns/latest/dg/) HTTP subscriptions to topics.
+ Use the [S3 transfer utility](https://docs.aws.amazon.com/mobile/sdkforxamarin/developerguide/s3-integration-transferutility.html) to transfer files to Amazon S3 from your Xamarin applications.
+ Use [Amazon Simple Queue Service (Amazon SQS)](https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/) to process messages and workflows between components in a system.
+ Perform efficient Amazon S3 transfers by sending SQL statements to [Amazon S3 Select](https://docs.aws.amazon.com/AmazonS3/latest/userguide/selecting-content-from-objects.html).
+ Create and launch [Amazon EC2](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Instances.html) instances, and configure and request Amazon EC2 [spot instances](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-spot-instances.html).

## Additional topics in this section
<a name="welcome-additional-topics"></a>
+ [AWS tools related to the AWS SDK for .NET](related-tools.md)
+ [Platforms supported by the AWS SDK for .NET](net-dg-supported-platforms.md)
+ [AWS SDKs and Tools Reference Guide](sdks-and-tools-ref.md)
+ [Revision history](revision-history.md)
+ [What's new in the AWS SDK for .NET](whats-new.md)
+ [Additional resources](net-dg-additional-resources.md)