Monad Shell (MSH) is Microsoft’s next generation shell for Windows. It’s a new scripting language, which is based on the idea of small commands that can be used together to create powerful scripts.
The shell is very impressive by itself. However, as part of their .NET strategy, Microsoft lets you import .NET libraries and use them from Monad scripts, which gives the programmer a lot of power.
ArsTechnica has a guided tour of Monad. It’s lengthy, but worth the read.
(For the computer language geeks among you, I will say that the new language is mostly procedural but also has functional properties, which makes it even more attractive.)