Laverna is a JavaScript note taking application with Markdown editor and encryption support.

TiddlyWiki is an open-source single page application wiki in the form of a single HTML file that includes CSS, JavaScript, and the content.

RedNotebook is an open source diary and journal software for Linux, Windows and Mac.

Kontact is a personal information manager and groupware software suite developed by KDE. It supports calendars, contacts, notes, to-do lists, news, and email.

KOrganizer is the calendar and scheduling component of Kontact, the integrated personal information manager from KDE.

XnView MP is the enhanced version of XnView Classic. It is a powerful cross-platform media browser, viewer and converter.

Raindrop.io syncs bookmarks into the cloud and makes them beautiful as well as easy to search.

Org-mode is an Emacs Mode for Notes, Planning, and Authoring.

Vosae is an invoicing, organizer, contacts app.