RabbitMQ - RabbitMQ is an open source message broker software.
Invoice Template - Create beautiful looking invoices in seconds
Ethereum - Ethereum is a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.
Billdu - Professional invoice maker for small businesses and freelancers
Hyperledger - Hyperledger is a multi-project open source collaborative effort hosted by The Linux Foundation, created to advance cross-industry blockchain technologies.
Free-Invoice.co.za - Free Invoice Software | Free online tool that helps small businesses to generate free invoices and manage their contact list. It can be used as an alternative to expensive invoicing software and online invoicing applications