In the blog Introducing Microsoft ASP.NET WebHooks Preview, we gave an overview of how to work with Microsoft ASP.NET WebHooks. Out of the box we provide support for a variety of existing WebHooks providers such as Dropbox, GitHub, MailChimp, PayPal, Slack, Trello, and many more.
Salesforce does not support classic WebHooks, but they do have a concept called Outbound Soap Messages which shares many of the same characteristics. As a result, it is possible to receive these messages using ASP.NET WebHooks.
For full story, see the blog Integrating with Salesforce using ASP.NET WebHooks Preview.