5pm is a Web-based project and task management software.

Apple Mail is an email client included with the operating systems macOS, iOS and watchOS by Apple Inc.

Basecamp is a project management web app.

Bugzilla is a web-based general-purpose bugtracker and testing tool.

EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries, e…

FogBugz is an integrated web-based project management system featuring bug/issue tracking, discussion forums, wikis, customer relationship management, and evi…

Airmail is a fast mail client for Mac and iPhone.

Asana is a web and mobile application designed to help teams track their work.

Bitrix24 is a free (for small businesses) social enterprise platform.

Claws Mail is a free and open-source, GTK+-based email and news client. It offers easy configuration and an abundance of features.

Evolution is the official personal information manager for GNOME.

Freedcamp is a web-based project management tool and organization system for single or multiple users collaborating using cloud computing.