Umbraco .Net CMS system
To follow Scott Guthrie about CMS tools, Clare Dillon mention also a cool CMS system done in .Net, Umbraco (free open source).
Don’t forget also my ‘humble’ contribution with dScribe 2.02 (freeware using .Net 1.1) still alive and doing well the job for a dozen sites.
If you are interested contact me on my blog.