One of the new features of the up-coming NSClient++ 0.4.0 will be Python scripting support. The main reason for me to include Python script (apart from the coolness factor) is to write unit tests. Writing unit test for a monitoring agent with a C++ unit test kit is pretty difficult but more importantly not very productive. The main feature of an agent is to interact with the system and thus you need to know about the system to be able to test it (or mock the system which is tedious at best).