Let's Chat is a persistent messaging application that runs on Node.js and MongoDB. It's designed to be easily deployable and fits well with small, intimate teams.
License: Open Source
Skype offers a comprehensive solution for video and voice calling, making it ideal for business and personal use, while Let's Chat emphasizes security and team collaboration with features like end-to-end encryption and chat bots. Skype is better suited for users who prioritize calling features, whereas Let's Chat is advantageous for those looking for a secure messaging platform.