Redmine is a flexible project management web application using the
Ruby on Rails framework, it is cross-platform and cross-database.

Redmine 4.2 introduces these new features in these categories:

Authentication / User accounts
* two-factor authentication.
* email domains restriction for user accounts.

Notifications
* Notify users about high issues (only).

Issues
* Bulk addition of related issues.
* Query links for subtasks on issue page.

And more:

Watchers
Text formatting
Keyboard shortcuts
Activity improvements