Wordnets are lexical databases in which words are organized into clusters based on their meanings, and they are linked to each other through different semantic and lexical relations. The first wordnet called the Princeton WordNet was created for English, which were followed by various wordnets created within the framework of the EuroWordNet and BalkaNet projects, among others. Here we focus on the development of wordnets in general and of the Hungarian WordNet (HuWN). The process of constructing HuWn is illustrated by examples, some language-specific and language-independent problems encountered during the construction process are discussed, and then basic statistical data on HuWN are presented as well. Finally, two subontologies of HuWN, namely, the financial domain ontology and the legal domain ontology are also presented, and possible applications of WordNets are outlined.