Knowledge Discovery Metamodel addresses the need to integrate various software tools that analyze ”existing software systems”. It allows to represent all the software artifacts recovered during reverse engineering techniques at different abstraction levels. This need was first realized by the so-called ”software modernization” community – a mature industry of tool providers that support maintenance and evolution phase of software development. Now, the idea of deep semantic integration based on open standard ontology was embraced by several Application Lifecycle Management Tool companies and Static Code Analysis community. This article focus on “software, kdm, tools, existing”.