Melissa-AI (https://github.com/melissa-ai/) is a cross platform virtual assistant that runs on Windows, Linux and MacOS. Enabling it on a raspberry pi server, you can control home automation, your social media as well as custom robots. Melissa makes homes and work smarter and is especially useful for people with physical disabilities. Melissa also integrates seamlessly with Rapiro (http://www.rapiro.com) to voice control the robot for day to day tasks. Melissa also operates between different devices and has been named as one of the best open source alternatives to Amazon Echo.