TiddlyAIR is a project mainly written in JavaScript, it's free.
Experiment bringing TiddlyWiki to Adobe AIR
I've made a TiddlyWiki that is wrapped up in an Adobe AIR container as a standalone app. The original TiddlyWiki still opens in a browser and functions normally (although its store is kept separate in the AIR app's storage directory).
Point of this: to try out a TiddlyWiki in a controlled environment where "save changes" isn't a big pain.
Restrictions: cookies don't work yet; import doesn't work yet. I haven't looked into these problems though.
To use: