What is "espacenet"

Espacenet (formerly often written as esp@cenet) is a free online service for searching patents and patent applications. Espacenet was developed by the European Patent Office (EPO) together with the member states of the European Patent Organisation. Most member states have an Espacenet service in their national language, and access to the EPO's worldwide database, most of which is in English. In 2015, the Espacenet worldwide service claimed to have records on more than 90 million patent publications.