RabbitMQ - RabbitMQ is an open source message broker software.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Ethereum - Ethereum is a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.
Invision - Prototyping and collaboration for design teams
Hyperledger - Hyperledger is a multi-project open source collaborative effort hosted by The Linux Foundation, created to advance cross-industry blockchain technologies.
Sketch - Professional digital design for Mac.