How to add ILNumerics controls manually to the Visual Toolbox Window: (from: http://ilnumerics.net/quickstart.html)
"ILNumerics controls are automatically listed in the Toolbox, once ILNumerics is installed into your project. However, in case the ILNumerics controls are not listed in the Toolbox, you can add them manually: Right Click onto the Toolbox, select 'Choose Item'. A dialog opens up and allows you to select the assembly to load controls from. If you have installed ILNumerics via NuGet, the ILNumerics.dll will be found under 'packages/ILNumericsX.X.X/lib' inside your project folder."
Note that it might be a good idea to clear the toolbox from any existing copies of custom controls. In order to reset the toolbox, right click on it and choose: "Reset Toolbox". Afterwards, use the method described above to add ILNumerics Controls to the fresh Toolbox.
Since ILNumerics is a regular .NET library, it could be installed into the GAC instead of using NuGet. Native dependancies would go into the corresponding Windows folders 'System32' and 'SysWOW64' folders. However, we currently do not support the GAC, because NuGet brings so much more convenience in terms of updates and dependency tracking as well as a smooth installation into the project and onto end user machines. What are your concerns regarding NuGet utilization? HD space is cheap nowadays .. ? ;)