The abbreviation ZET (pronounced voiced sett) stands for the operator of the public transport network of the Croatian capital Zagreb. Originally ZET was the operating company of the Zagreb tram (Croatian: Zagrebački električni tramvaj, German:) Zagreb Electric Tramway. The company has evolved, but also for the operator of numerous urban transportation bus services in Zagreb and the surrounding area. In colloquial use are therefore called the ZET Zagreb lines in general, while the trams as simply tramvaj (tram) refers. There already are plans for the construction of an underground tram line through Zagreb.