Hello, For those that use .NET as a backend as you know there are not many options and most have vaniss from the web a long time ago or stopped the development. Meanwhile .NET Core (now just .NET 5) was developed and there was not a single option for AMF.
I developed AMFCore 2 years ago based on .NET Standard and not on .NET Framework, so it works on all .NET implementations (.NET Framework, Mono, .NET Core and now .NET). Also, this library doesn't require the ASPX gateway that is only supported for WebForms solutions that were discontinued. Tested on all implementations and with full example for all cases on the readme page. Recently this library was updated to works with Apache Royale SimpleRemote, so the same .NET backend works with a Flex application with RemoteObject and Apache Royale with SimpleRemote. As I seen recently people using .NET here on the mailing list, I remembered to share this library: https://github.com/SolidSoft-Lda/AMFCore Of course it's free and open source.