The best open source alternative to TiddlyWiki is Zim, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to TiddlyWiki and many of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to TiddlyWiki are BookStack (Free, Open Source), MediaWiki (Free, Open Source), Trilium Notes (Free, Open Source) and DokuWiki (Free, Open Source).
Foam is a personal knowledge management and sharing system inspired by Roam Research, built on Visual Studio Code and GitHub. You can use Foam for organising your research, keeping re-discoverable notes, writing long-form content and, optionally, publishing it to the web.
TiddlyRoam is your open source external brain. TiddlyRoam allows you to quickly create your own wiki. You can add fragments of thoughts and findings whenever they come to you. TiddlyRoam will link them and help you spot the patterns.
WRITE OFFLINE You can write/edit your notes on your laptop even if you are offline. MULTIPLE DEVICES Boostnote is available for browser, desktop and mobile. SYNTAX HIGHLIGHT Boostnote can highlight code syntax in more than 100 languages.
Dokit makes your documentation accessible in just a few clicks on all media (PC, mobile, machines) and integrates with your existing systems (CMMS, PLM, LMS). Easily adapt the platform design to your graphics. Enable single sign-on to make it easier for your users to log in.