The construction of plWordNet began in 2005 and has been continued since then. In this paper we present the latest 5.0 version and describe the challenges connected with a life-long wordnet development process. These involve changes in the procedures and lexicographers' teams, the necessity to extend the lexical description, and the need to link to external resources (Princeton WordNet, sense-tagged corpora, and valence dictionary). We describe different strategies and diagnostics implemented to improve the quality of the resource.