Ethereum - Ethereum is a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.
draw.io - Online diagramming application
RabbitMQ - RabbitMQ is an open source message broker software.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Hyperledger - Hyperledger is a multi-project open source collaborative effort hosted by The Linux Foundation, created to advance cross-industry blockchain technologies.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.