Specflow is an OpenSource .Net BDD tool.
The workflow to create a running SpecFlow scenario is as follows:-
1. Add a reference to the TechTalk.SpecFlow DLL in the project that will contain your features.
2. Add feature files, step definitions and event definitions
3. Write a feature specification in the Gherkin format
4. Write step definitions and event definitions in C#
5. Execute generated unit-tests with a unit test runner
More information at - http://www.specflow.org/
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