Since its launch in 1993, Encarta has become the dominant electronic encyclopaedia and helped effectively kill off the concept of a print encyclopedia. The 2006 Australian reference library version (which can be installed from either CD or DVD) incorporates a dictionary, atlas, and specialised children's material, but doesn't entirely meet the rising challenge of online reference sources such as Wikipedia.

Installation is straightforward, although slow; the space-challenged can choose to access content from the DVDs or CDs, but copying to your local hard drive gives much better performance. The package includes 68,000 articles, 25,000 illustrations, and 1.8 million map locations, as well as specialised video content from the Discovery Channel and selected newspaper excerpts from the Times. Specialised local content has been added to the Australian edition, although annoyingly there's no way of telling the dictionary to use Australian rather than American English spelling.

Navigation through Encarta is straightforward. You can browse by category or read selected entries, but most users are likely to simply type a term into the search bar and check what appears. Related articles and media are clearly listed in a separate table.

Even allowing for the inherent constraints of encyclopaedia entries, the content is somewhat variable. Some entries (such as those for Linux) show evidence of corporate bias. Others, such as the description of the MP3 file format, are just plain inaccurate. Many entries show an imbalance, with much more detail on recent events -- presumably a legacy of Microsoft's adding new information to content acquired from third parties. Some odd decisions have been made concerning what data is included (such as a lack of birth or death dates for biographical entries) and there could be more extensive use of linking, especially in the supplementary materials.

One potentially useful addition is the Encarta Web Companion, which adds a search toolbar to Internet Explorer and allows you to try existing Web searches against Encarta's contents. Encarta also offers an auto-update service to incorporate new information, although you need to have a Microsoft Passport membership and the updates themselves are fairly hefty (more than 50MB the first time we installed them).

Microsoft's positioning of Encarta is that it offers an authoritative source of information, as opposed to the random and unsubstantiated nature of much online information. It remains a useful reference tool for quick fact-checking, and for families it minimises the risk of children accessing unsuitable material while researching a topic. However, are enough problems in its content that you may well need to supplement its information with community-edited resources like Wikipedia.