OnixS low-latency .NET FIX Engine is a .NET class library that FIX-enables applications written in .NET supported languages (C#, Visual Basic (VB.NET), F#, Managed C++, etc.).
.NET Core/.NET 6 FIX Engine Programming Guide.NET Core/.NET 6 FIX Engine Release Notes
OnixS Support JIRA - .NET Core FIX Engine (JIRA user access permissions required)
.NET Core FIX Engine downloads (access permissions required)