This is a rewrite of Critical Path Method Implementation in C#. It has the following features over and above the original:

• It uses generics to avoid type dependency. Extra metadata is stored internally
• The public method is an extension method on IEnumerable, so any list works
• Task information can come in any order. Pass in a lambda to tell the engine how to get a task's predecessors and another lambda to get the task length and it will figure out the rest
• If a loop is detected in the path, an exception will be thrown

It is used in a production web site and is stable at this point