We currently target net452 and then either netstandard1.5 or netcoreapp2.1. By targeting  .NET Standard or Core first, we'll improve compatibility with other IDEs and editors such as Visual Studio for Mac and VS Code. Additionally, for Visual Studio, this will make is so that .NET Core is tested by default instead of .NET Framework (.NET Framework can still be tested in the IDE by manually reordering the declaration order or by using Resharper).

Note: This does not mean we will be officially supporting other IDEs.