Lightning Calendar Organize your schedule and events in a calendar fully integrated with Thunderbird or Seamonkey email. . Free Open Source Mac OS X Windows Linux Thunderbird SeaMonkey CalDAV CardDAV Add a feature 157 Like
Evolution Evolution is the official personal information manager and workgroup information management tool for GNOME. It combines e-mail, calendar, address book, and task list... Free Open Source Linux BSD S/MIME GNOME OpenPGP Built-in RSS reader CalDAV Calendar integration CardDAV ... Encrypted email Integrated Spam Protection Multiple languages POP3 Support Add a feature 148 Like
RedNotebook RedNotebook is a graphical diary and journal helping you keep track of notes and thoughts. It includes a calendar navigation, customizable templates, export... Free Open Source Mac OS X Windows Linux PortableApps.com Xfce No features added Add a feature 98 Like
Quire Quire is a new-generation collaborative task management tool for organizing tasks in a tree-like structure wrapped in simple and user-friendly UI. Its unique visual... Free Mac Windows Linux Web Android ... iPhone Android Tablet iPad Chrome Hierarchical structure Subtasks Google Chrome extension Cloud sync ... Drag n drop Real time collaboration Team Collaboration Add a feature 89 Like
Geary Geary is an email application built for GNOME 3. It allows you to read and send email with a simple, modern interface. Free Open Source Linux BSD GNOME No features added Add a feature 69 Like
Org mode Org mode is for keeping notes, maintaining TODO lists, planning projects, and authoring documents with a fast and effective plain-text system. Free Open Source Mac Windows Linux Customizable Command line interface Emacs integration Export to HTML ... Hierarchical structure Hierarchical tagging Infinite hierarchical depth Portable Privacy focused Search by tags Tag based Add a feature 65 Like
Task Coach Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists. It is designed for composite tasks, and also offers effort tracking... Free Open Source Mac Windows Linux iPhone BSD ... iPad PortableApps.com Portable Add a feature 118 Like
Restyaboard Open source Trello-like kanban board. Based on Restya platform. Free Open Source Linux Web Self-Hosted Gantt-charts Kanban boards Real time collaboration Add a feature 51 Like
Todo.txt Track your tasks and projects in a plain text file, todo.txt. A todo.txt is software and operating system agnostic; it's searchable, portable, lightweight and... Free Open Source Mac OS X Windows Linux Android iPhone ... Android Tablet BSD iPad Command line interface Portable Add a feature 54 Like
TreeSheets The ultimate replacement for spreadsheets, mind mappers, outliners, PIMs, text editors and small databases. Suitable for any kind of data organization, such as To-do... Free Open Source Mac OS X Windows Linux No features added Add a feature 51 Like
Kontact - KMail KMail is the email component of Kontact, the integrated personal information manager of KDE. Kontact is a personal information manager and groupware software suite for... Free Open Source Mac OS X Windows Linux BSD No features added Add a feature 30 Like
Kontact Kontact is the integrated Personal Information Manager of KDE. Kontact suite unites mature and proven KDE PIM applications under one roof. Thanks to the powerful... Free Open Source Windows Linux No features added Add a feature 25 Like
Nitro Super awesome task management. Nitro is the best way to get things done. It's simple, fast and powerful at the same time. Nitro also syncs with Dropbox or Ubuntu... Free Open Source Mac OS X Linux Web No features added Add a feature 25 Like Discontinued Latest commit d44b5db on Mar 29, 2014: https://github.com/CaffeinatedCode/nitro
Zimbra Desktop The free Zimbra Desktop client allows you to meld the online and offline worlds – storing and synching your email, calendar, contacts, files and documents in the cloud... Free Personal Mac OS X Windows Linux No features added Add a feature 29 Like
GeeTeeDee GeeTeeDee is a fancy, lightweight, easy to use and effective task management software. Free Mac OS X Windows Linux Lightweight Portable Add a feature 18 Like Discontinued The program is no longer updated. Last versions, released in December 2014, can be still downloaded from the official website.
