The Amazon SDK for .NET V3 has entered maintenance mode.

We recommend that you migrate to [Amazon SDK for .NET V4](https://docs.amazonaws.cn/sdk-for-net/v4/developer-guide/welcome.html). For additional details and information on how to migrate, please refer to our [maintenance mode announcement](https://aws.amazon.com/blogs/developer/aws-sdk-for-net-v3-maintenance-mode-announcement/).

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

(**OK, got it\$1** I'm ready to [set up](net-dg-config.md) and [take a quick tour](quick-start.md).)

## About this version
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**Current and past documentation**  
This documentation is for version 3 (V3) of the Amazon SDK for .NET. V3 isn't latest version of the SDK. For the latest version of the SDK, see the [Amazon SDK for .NET (V4) Developer Guide](https://docs.amazonaws.cn/sdk-for-net/v4/developer-guide/welcome.html).  
This documentation is 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 [Migrate your project](net-dg-migrating.md).  
To find deprecated content for earlier versions of the SDK, see the following item(s):  
[Amazon SDK for .NET (version 2, deprecated) Developer Guide](samples/Amazon-sdk-net-v2-dg__deprecated-content.zip)
[Deprecated API references for the Amazon SDK for .NET](sdk-api-ref.md#about-api-versions)

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

## Common use cases
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The Amazon SDK for .NET helps you realize several compelling use cases, including the following:
+ Manage users and roles with [Amazon Identity and Access Management (IAM)](https://docs.amazonaws.cn/IAM/latest/UserGuide/).
+ Access [Amazon Simple Storage Service (Amazon S3)](https://docs.amazonaws.cn/AmazonS3/latest/userguide/) to create buckets and store objects.
+ Manage [Amazon Simple Notification Service (Amazon SNS)](https://docs.amazonaws.cn/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.amazonaws.cn/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.amazonaws.cn/AmazonS3/latest/userguide/selecting-content-from-objects.html).
+ Create and launch [Amazon EC2](https://docs.amazonaws.cn/AWSEC2/latest/UserGuide/Instances.html) instances, and configure and request Amazon EC2 [spot instances](https://docs.amazonaws.cn/AWSEC2/latest/UserGuide/using-spot-instances.html).

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