Capturing and analysing output from a launched/shelled process

It is useful in lots of places to be able to capture and display the output from an application that was launched and base decisions on that output or else display progress to the user based upon that output. Here is a fully working example of such a class. There are a number of threading issues covered in this example. This is currently used in our build environment and in subversion hooks to analyze the output in pre-commit hooks to determine if the changes are allowed to the repository.