TiddlyWiki is a single html file with all the characteristics of a wiki - including all of the functionality (including editing, saving, tagging and searching) and the style sheet. Because its a single file, its very portable - you can email it, put it on a web server or share...
Zim brings the concept of a wiki to your desktop. Store information, link pages and edit with WYSISYG markup or directly typing some lightweight markup syntax and see it previewed as-you-type. Creating a new page is easy by either clicking on the "Create new note"...
DokuWiki is a standards compliant, simple to use Wiki, mainly aimed at creating documentation of any kind. It is targeted at developer teams, workgroups and small companies. It has a simple but powerful syntax which makes sure the datafiles remain readable outside the Wiki and...
Free, open-source note-taking with rich text, cross-platform support, syntax highlighting, embedded files, and customizable interface.
XWiki is the ultimate open-source structured wiki designed to enhance business collaboration and efficiency. Tailored for tech-savvy professionals, XWiki’s extensibility, customization, and flexibility make it indispensable for managing large projects and datasets, while...
wikidPad is a Wiki-like notebook for storing your thoughts, ideas, todo lists, contacts, or anything else you can think of to write down. What makes wikidPad different from other notepad applications is the ease with which you can cross-link your information.
Made by the company behind 
WordPress, Simplenote enables users to take notes, lists, and ideas. These notes are stored on the cloud and are accessible across multiple devices.
End-to-end encrypted note-taking with offline access, unlimited sync across devices, tagging, passcode and biometric security, plus advanced premium privacy features.
Open source note-taking app with Markdown support, to-do integration, and synchronization with cloud services like Dropbox and OneDrive.
