FIX has become the language of the global financial markets used extensively by buy and sell-side firms, trading platforms and even regulators to communicate trade information. This non-proprietary, free and open standard is constantly being developed to support evolving business and regulatory needs, and is used by thousands of firms every day to complete millions of transactions.
https://www.nuget.org/packages?q=QuickFIXn
dotnet add package QuickFIXn.Core --version 1.10.0 dotnet add package QuickFIXn.FIX4.0 --version 1.10.0 dotnet add package QuickFIXn.FIX4.1 --version 1.10.0 dotnet add package QuickFIXn.FIX4.2 --version 1.10.0 dotnet add package QuickFIXn.FIX4.3 --version 1.10.0 dotnet add package QuickFIXn.FIX4.4 --version 1.10.0 dotnet add package QuickFIXn.FIX5.0 --version 1.10.0