OpenXava - OpenXava is a Web Java Framework for Rapid Development of Enterprise Applications.
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
jHipster - JHipster is a development platform to quickly generate, develop, & deploy modern web applications & microservice architectures.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Spring Framework - The Spring Framework provides a comprehensive programming and configuration model for modern Java-based enterprise applications - on any kind of deployment platform.
eM Client - eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.