RabbitMQ - RabbitMQ is an open source message broker software.
MJML - The open source framework for responsive emails
Ethereum - Ethereum is a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.
Stripo - Stripo is an all-in-one email design platform. We enable our clients to build emails of any complexity, including interactive AMP emails, really fast and easy.
Hyperledger - Hyperledger is a multi-project open source collaborative effort hosted by The Linux Foundation, created to advance cross-industry blockchain technologies.
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.