MshSnapinBase (or MshSnapinInstaller) is a class for facilitating registry of necessary information for monad mshsnapin's.
This class will be built with monad core engine dll (System.Management.Automation.dll). This is the base class for two kinds of mshsnapins: MshSnapin and CustomMshSnapin. Each mshsnapin assembly should derive from this class (indirectly) and fill in information about mshsnapin name, vendor, and version. At install time, installation utilities (like InstallUtil.exe) will call install this engine assembly based on the implementation in this class. This class derives from base class PSInstaller. PSInstaller will handle the details about how information got written into registry. Here, the information about registry content is provided. The reason of not calling this class MshSnapinInstaller is to "hide" the details that MshSnapin class is actually doing installion. It is also more intuitive since people deriving from this class will think there are really implementing a class for mshsnapin.
public abstract class PSSnapInInstaller : System.Management.Automation.PSInstaller
This is an abstract class to be derived by monad mshsnapin and custom mshsnapin. MshSnapin developer should not directly derive from this class.