As software evolves and becomes more complex, self-adaptive systems become a moreinteresting solution. Self-adaptive software systems are capable to perform changes inthemselves without human intervention. To make this possible it is necessary toperform a good observation of the system and its environment. This observation is madeby a monitoring system.In this paper, a framework for monitoring OSGi based applications is presented.OSGi is a module system and service platform for Java. This framework offers run-timeinformation about OSGi modules, services and their behavior.The first step is to make a state-of-the-art survey of existing methods to monitor inthe field of self-adaptive systems and OSGi based applications. The survey reviews aset of articles in the area. It is performed to discover what are the common objectivesand problems that any monitoring system faces. After that, the requirements for theframework are stated. These requirements specify the functionality that the frameworkis required to provide, along with the quality attributes that it has to meet. Todemonstrate use of the contributed monitoring framework, we have developed twoexample demonstrators. The objective of these demonstrators is to provide users of theframework with working examples, so that they can use the framework to develop theirown monitoring systems.