.NET (pronounced 'dot net') is a software platform developed by Microsoft. There are many programming languages that all 'boil down' to .NET, for instance, C#, VB.NET, etc. In order to run a program written in a .NET language, you must have the '.NET Framework' installed on your computer. .NET is required for the old DCOM device connections (OPC-DA). FactorySQL is written in various .NET languages and runs on the .NET framework. This requirement is phasing out as more and more devices are available through OPC-UA drivers.