Hey, Silviu! Very interesting photos! Good news is that some of those trams and busses in the pictures still exist and they are running but as historical vehicles. If you are interested, the
Wikipedia has a well done article on this subject.
Right now trams are of greatest importance to the city council in Poznan. They are adding new lines to the network once in a while and some big investments are on the way. I particularly like the idea of a fast tram which runs on separate tracks on different levels than normal streets - in excavations, tunnels and in places that were designed not to be accessed by road. The trams run there 50km/h all the time so traveling across a 6km section of the line takes only 10 minutes. The same distance takes an hour to travel on feet and almost half an hour by car. It's like a stripped version of a metro line and it's probably cheaper to build than other mass transit systems.