Local Area Wiki
I'm an ardent user of the desktop wiki Zim, which is a very handy tool to organize ones own notes and ideas. Zim also offers a built-in webserver which allows users in the same network to glance upon these notes and ideas. The exported web site cannot, however, be edited directly, and this feature is thus less useful for an actual sharing of notes in a wiki-style sense. There are also a number of other features which Zim lacks in this context. Tags, for example, are indispensable for filtering the displayed content in what I planned to set up, namely, a shopping list.
I've spend a few hours looking around and finally concluded that TiddlyWiki is ideally suited for the kind of local area wiki I envisioned. It consists of a single html file which can be directly edited in a modern web browser and saved locally (with the Firefox extension TiddlyFox, Java does not need to be enabled in the browser).
I basically use the default design with only a few changes of colors and font sizes defined in the shadow tiddlers 'ColorPalette' and 'StyleSheet':
The wiki, being physically located on a network share accessible by all family members, is then made avaliable in my LAN using darkhttpd as web server: