Update 19th of December 2012: I’m not sure that I’d advise anyone to use DillPickle 
not now that I’ve tried SpecFlow which is very cool, integrates well with Visual Studio and your build server, etc…
Introduction
DillPickle is a slim Gherkin-compliant BDD story runner for .NET.
It has borrowed (stolen?) most of its functionality from NBehave, but has some hooks I needed and some more nifty stuff.
Source code and stuff is on Github, including the “official” documentation wiki.
What?
You can write high level, understandable-by-business-people, understandable-and-easily-writable-by-developers executable specifications in Gherkin and have DillPickle run them… check this out:
Feature: User login
As a user
I want to be able to sign in to my account
So that I can use the site as myself
Scenario: Successful login
Given I am visiting the front page
and the following accounts exist:
| username | password |
| mookid8000 | secret! |
When I type "mookid8000" in textbox username
and I type "secret!" in textbox password
and I click "Sign in"
Then I am redirected to my home page
and a notification reads "Welcome mookid8000"
Scenario outline: Failed login
Given I am visiting the front page
and the following accounts exist:
| username | password |
| mookid8000 | secret! |
When I type "<username>" in textbox username
and I type "<password>" in textbox password
and I click "Sign in"
Then I am redirected to the front page
and a notification reads "Wrong username and/or password"
Examples:
| username | password |
| mookid8000 | wrongPassword |
| wrongUsername | doesntMatter | |
- and all this stuff can be executed and verified by DillPickle! Nifty, huh?!