Technologies Desktop Search

Desktop search engines build and maintain an index database to achieve reasonable performance when searching several gigabytes of data. Indexing usually takes place when the computer is idle and most search applications can be set to suspend it if a portable computer is running on batteries, in order to save power. When indexing the files, desktop search tools collect three types of information about files:

* file and directory names
* metadata, such as titles, authors, comments in file types such as MP3, PDF and JPEG
* content of supported documents.

To search within documents, the tools need to be able to parse many different types of documents. This is achieved by using filters that interpret selected file formats. For example, a Microsoft Office Filter might be used to search inside Microsoft Office documents.

Long-term goals for desktop search include the ability to search the contents of image files, sound files and video by context.

The sector attracted considerable attention from the struggle between Microsoft and Google. According to market analysts, both companies are attempting to leverage their monopolies (of web browsers and search engines, respectively) to strengthen their dominance. Due to Google's complaint that users of Windows Vista can not choose any competitor's desktop search program over the built-in one, an agreement was reached between US Justice Department and Microsoft that Windows Vista Service Pack 1 will enable users to choose between the built-in and other desktop search programs, and select which one is to be the default.