We just love it every time Google comes up with its catchy and quirky doodles on important days and events. So, here is a classic retro doodle right on the occasion of its birthday. The world's most popular internet search engine is celebrating its 17th birthday with a doodle which shows an old plastic PC, a lava lamp and a Linux penguin peeking from behind the monitor. The monitor display shows the first Google home screen when it had launched back in 1998.