The paper presents the framework and the main tools for software maintenance (i.e creation and management of versions), developed during the !ST project called MECASP (Maintenance and improvement of component-based applications diffused in ASP mode). The specific features and general architecture ofMECASP, given at the beginning of the paper, make it differ from the existing (open source and commercial) produ is for version management. 1l1e paper gives a brief description of the software architecture in MECASP, represented by XML meta-models and versioned models. Also, it presents the basic components of the specific browser in MECASP. Among the problems to be solved for the implementation of MECASP (most of them from scratch), the paper emphasizes the issues for the implementation of an open source-based XML repository manager and of a rule-based and semantically enhanced merge strategy, devoted to the maintenance of heterogeneous types of software. The use ofMECASP for software maintenance and adaptation is exemplified by the use cases given at the end of the paper, for both software design and deployment phases.
Software maintenance, XML models, XML repository manager, open source software