I use DDay.Ical, its good stuff.
Has the ability to open up an ical file and get its data in a nice object model. It says beta, but it works great for us.

Edit Nov 2016

This library has been deprecated, but was picked up and re-released as iCal.NET by another dev.

Notes about the release: rianjs.net/2016/07/dday-ical-is-now-ical-net

Source on GitHub: github.com/rianjs/ical.net