FreeLing is an open-source open-source multilingual language processing library providing a wide range of language analyzers for several languages. It offers text processing and language annotation facilities to natural language processing application developers, simplifying the task of building those applications. FreeLing is customizable and extensible. Developers can use the default linguistic resources (dictionaries, lexicons, grammars, etc.) directly, or extend them, adapt them to specific domains, or even develop new ones for specific languages. This paper presents the semantic services included in FreeLing, which are based on WordNet and EuroWordNet databases. The recent release of the UKB program under a GPL license made it possible to integrate a long awaited word sense disambiguation module into FreeLing. UKB provides state of the art all-words sense disambiguation for any language with an available WordNet.