What are the best application frameworks to build IoT / IIoT Applications?

Extendable & Scalable MQTT Broker for all your IoT/IIoT Implementation.
Complete IoT Application framework to build faster IoT Applications.
Powerful & flexible security options for enhanced data security.
Application/Mobile integration using RestAPI.
Flexible integration with any database or big data engine for perfect analysis & decision-making.
Custom Dashboard to visualize the data in the way you need it.
Advanced ML/AI integration for customized data processing.
Custom Authentication with IAM/SSO tool integration.