nanoFramework is a free and Open Source platform that enables the writing of managed code applications for constrained embedded devices.
As a developer, you can use your powerful and familiar tools like Microsoft Visual Studio IDE and your .NET C# skills to write code on your microcontroller.
nanoFramework already supported the FeatherS2, but they just released support for ESP32-S3 boards, including the FeatherS3!
Check out their getting started guide as well as their support guides for ESP32-S2 and ESP32-S3.