RabbitMQ - RabbitMQ is an open source message broker software.
Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.
Ethereum - Ethereum is a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Hyperledger - Hyperledger is a multi-project open source collaborative effort hosted by The Linux Foundation, created to advance cross-industry blockchain technologies.
Cardbox - Contacts reimagined as a social network ✨