Fantastical is a flexible calendar with natural language event creation, a beautiful calendar and event list, support for CalDAV (including Google Calendar delegates) automatic alarms, and instant searching.
Kalendar is a Kirigami-based calendar application that uses Akonadi. It lets you add, edit and delete events from local and remote accounts of your choice, while keeping changes syncronised across your Plasma desktop or phone.
Own your time with Calendars by Readdle across all your Apple devices – Mac, iPhone, iPad, and Apple Watch.
Appointments and reminders, meetings and deadlines, birthdays and dates - make the most of your time with Calendar 366 II!
qOrganizer is a general organizer that includes a calendar with schedule,reminders,journal/notes for every day, to-do list.Discontinued
The project is no longer developed. Last version, 3.1.5, released in August 2010, can be still downloaded from SourceForge.
InstaCal is an affordable, yet powerful calendar app that puts all your events right at your fingertips, always available in your Mac's menu bar. InstaCal is quick and convenient, and can be opened at any time with a configurable keyboard shortcut.