# eXtremeSQL C# API

This article is only applicable to .NET Framework 4.x and .NET 8 (former .NET Core) on Windows. eXtremeDB for .NET 5 (on Windows, Linux) and later is documented in the eXtremeSQL C# API for .NET Core articles.

> eXtremeSQL is implemented as a compact set of C# classes in pre-built libraries that provide SQL access to eXtremeDB databases. The usage of these classes is demonstrated in the SQL C# SDK Samples. For developers new to eXtremeSQL, we recommend the Quick Start tutorial to quickly learn the programming fundamentals. Then proceed to build and run the SDK samples.

> Please use the following link for general principles of embedded eXtremeSQLapplication implementation using the C# API.

> Example | A simple C# application example
> Misc Details | Miscellaneous C# implementation details
> SqlAggregator | Instructions for using the SqlAggregator class