Microsoft Bot Framework

Microsoft Bot Framework (MBF) provides an open-source platform for building bots. Microsoft’s approach is primarily code-based and exclusively targets developers. MBF offers developers precise control over the chatbot building experience and access to numerous out-of-the-box functionalities and connectors.

The MBF term encompasses a fantastic array of tools to assist in the chatbot creation process. It can also integrate with LUIS, its natural language understanding engine. Microsoft has also acquired Botkit, another open-source platform. Botkit is more of a visual conversation builder with a greater focus on user interface actions available to the user.

MBF cannot be considered completely open source, as the NLU engine it uses, LUIS, is proprietary software. This may be an issue for you, depending on your situation regarding the need for more control.

One disadvantage of not having an open-source NLU engine is that it cannot be installed on-premises. This is again a concept from Microsoft, as MBF and LUIS are partially integrated products to promote the use of its Azure platform. LUIS is a service that charges per API call, which can translate into a hefty monthly bill.