Wiki Offline Lite is a desktop client for Wikipedia. The most interesting feature that this application has to offer is that it can let you access Wikipedia articles while you are offline. The "lite" version comes packaged with 1000 of the most popular wikipedia articles. The full version lets you download the whole Wikipedia database in your language of choice for offline access.
The graphical user interface is very plain, which makes it easy for you to read articles on your Mac. At the top of the screen, you will find a text field where you can type in your search keywords. Articles will be listed as you type, and you can simply click on one of the suggestions to go to that article. If your search query isn't among the 1000 most popular articles that come with the "lite" version, no suggestions will be made. On the left part of the screen, there are three buttons: Bookmarks, History and Contents. Bookmarks shows the list of bookmarked articles. History shows your recently-viewed articles and Contents lets you go to different parts of the active article.
In short, Wiki Offline Lite is a nice tool to browse Wikipedia offline. The lite version isn't very useful because it is limited to 1000 articles, though.