The development of knowledge-based (KB) systems for solving real-world problems has become a very time-consuming and expensive task. Over the last years, more and more people started to investigate how to share and reuse knowledge once it has been formally represented. Moreover, as the world around is changing continuously, the KB system and its knowledge base have to change, too. Thus, recently the issue of knowledge base evolution came up that deals with the continuous improvement of a KB system during its entire life-time starting with the first formalizations and still continuing along its practical use. We discuss the current efforts in knowledge sharing and reuse and then study the knowledge evolution approach, that can be seen more technically as an interleaved combination of knowledge validation and exploration techniques
