Mruby is a lightweight implementation of the Ruby programming language that is well-suited for developing applications for the Internet of Things (IoT). The IoT involves connecting physical devices to the internet to collect and exchange data. Mruby allows for easy development of embedded systems that can communicate over the internet. Several example applications developed with mruby were shown, including a smart umbrella, live sensor monitoring, mobile event notifications, and social media integration. These applications interface with external APIs and sensors to retrieve and transmit data for IoT use cases.