Nowadays, people have a wide range of possibilities of access to information. As the Internet constantly expands, the amount of available on-line information expands correspondingly. Although, it is getting easier and easier to get the information, the required piece of information is very often mixed with less important or even useless information. Information retrieval is currently one of the most important usages of the Internet. Agent technology is a promising and enabling technology, not only useful for distributed information retrieval but also for ecommerce applications. There has been tremendous interest in the past few years in using mobile agent technology for next-generation enterprises. In particular, mobile agents seem have been proposed for automating the task of retrieving, organizing and filtering information located at widely dispersed sites. Mobile agents are processes (e.g. executing programs) that can migrate from one machine of a system to another machine (usually in the same system) in order to satisfy requests made by their clients. Mainly, a mobile agent executes on a machine that hopefully provides the resource or service that it needs to perform its job.