The Microsoft Bot Framework is a code-first bot creation tool: https://dev.botframework.com/
The learning curve is steeper than other similar solutions', because you actually need to write code, but if you are familiar with C# or JS, the possibilities are much wider than with the others.
The official docs are pretty good, in the design section it also explains some base concepts of conversation design, not just how to use the SDK-s: https://docs.microsoft.com/en-us/azure/bot-service/bot-servi...
Having heard about this while never using it and having used other "hot" frameworks that Microsoft gave up on (Xamarin) and having checked out hyped products that turned out to be underdeveloped (windows iot) I have doubts about how good their chat framework is since the future didn't turn out to be all about chat bots like they said it would.
