From the site of TiddlyWiki: http://www.tiddlywiki.com/
I am currently using this device as my documentary text database for my different writtings. Works fine within Firefox. Since it is self contained I think it does not write anywhere. You can generate a complete web page in a single file. In my web page there is a piece of this in the link 'TTK-news'.TiddlyWiki is a complete wiki in a single HTML file. It contains the entire text of the wiki, and all the JavaScript, CSS and HTML goodness to be able to display it, and let you edit it or search it. Without needing a server.
TiddlyWiki is published under an OpenSourceLincense and maintained by a busy Community of independent developers.
...
Out of the box, TiddlyWiki offers:
* Browsable with the vast majority of modern desktop browsers on Windows, Macintosh and Linux
* Ability to SaveChanges on:
o FireFox and Opera under all operating systems
o InternetExplorer under Windows
o Safari and Camino under OS X
o Minimo on Nokia 770
* Rich formatting including MonospacedText, ExtendedFormatting, NonWikiWordLinks, WikiWordEscape, PrettyLinks, SubHeadings, BulletPoints, NumberedBulletPoints, Tables, BlockQuotes, HorizontalRules and the ability to use a CustomCssClass.
* Various InterfaceOptions, including the ability to GenerateAnRssFeed, SaveBackups and AutoSave
* KeyboardShortcuts so you can finish editing a tiddler with Control-Enter or abandon it with Escape
* InlineHTML
* ...EmbeddedImages:
* Macros providing rich interactive features, including Sparklines and Gradients
* a flexible OpenSourceLicense
* a liquid CSS layout that can be customised with a CustomStyleSheet
* Extensive StartupParameters to control the behaviour of TiddlyWiki through specially crafted URLs
* There are translations of TiddlyWiki available in many languages, including Chinese, French, German, Spanish, Portuguese
The Community around TiddlyWiki has extended this basic functionality with a wide range of Plugins and TiddlyWikiAdaptations.
Regards.
*JT.