September 17, 1988: The Seoul Olympics open. On 17 September 1988, the opening ceremony of the 24th Summer Olympics took place at Seoul Olympic Stadium. Many people still remember the moment a boy rolled a metal hoop across the quiet field. That hoop is now on display at the National Sports Museum, which opened in Olympic Park in 2026.
1543 π¨ The first book in the Finnish language, the 'Abckiria' by Mikael Agricola, was published in 1543; it was an ABC book to help people learn to read.
1961 π‘ The Civic Arena in Pittsburgh opened in 1961 as the world's first big sports arena with a roof that could open up to the sky.
1991 π‘ Student Linus Torvalds released the first version of the Linux kernel on the internet in 1991, and today Linux runs in phones, servers and supercomputers.