If you create software and need to perform durable processing of long-running activities, one of the things you can use is the Workflow Foundation libraries from Microsoft.

And if you’re using Castle Project you might want to take a look at the workflow integration facility. It’s recently had a demo website added to the solution, and documentation has been built up on the Castle Project wiki.

Putting it together was a very gratifying experience. Hopefully there are some people out in the world that will find such a thing useful. :)