NETBlock — release any .NET objects created during evaluation once evaluation finishes

BeginNETBlock, EndNETBlock — mark the beginning and end of a .NET block

KeepNETObject — allow a .NET object to persist when the current NETBlock ends

ReleaseNETObject — finish using a .NET object in Mathematica

SameObjectQ — whether two NETObject expressions reference the same .NET object

LoadedNETObjects — list of all .NET objects in use

LoadedNETTypes, LoadedNETAssemblies — list of all .NET types or assemblies in use