TiddlyWiki is an open-source notebook that its project site describes as "a unique non-linear notebook for capturing, organising and sharing complex information." Its official GitHub README calls it a complete interactive wiki written in 📝JavaScript that can run either as a single HTML file in a web browser or as a 📝Node.js application. As of November 2026, the homepage title reads "TiddlyWiki v5.4.1 — a non-linear personal web notebook."
According to the project site, TiddlyWiki stores its data and code in a single HTML file and requires no installs, and it lets users choose where to keep their data. The README describes it as a notebook "that anyone can use and keep forever, independently of any corporation," and says its entire user interface is implemented in WikiText, which users can modify. The site adds that plugins extend TiddlyWiki with new features. Its licence page states that TiddlyWiki "is published under a permissive BSD 3-Clause License," explains that people can use it without paying a licence fee, and refers to it as an open source project. The project site describes TiddlyWiki as "the product of a collective of developers, part of an extensive community of users," and the README notes that the original TiddlyWiki group has been hosted on Google Groups since 2005.