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On 25 August 1991 Linus Torvalds, a 21-year-old student in Helsinki, announced online that he was writing a free operating system, 'just a hobby'. He shared the code for anyone to study and improve, and volunteers and companies turned it into Linux, which now runs much of the internet and every Android phone.

comp.os.minix, 25 August 1991

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Torvalds posted his announcement to comp.os.minix, an online discussion group about MINIX, a small teaching operating system he was using on his PC, and added that his project would not be 'big and professional'. Strictly, Linux is a kernel: the core of an operating system, which shares out the processor, memory and devices so that other programs can run. He first called it Freax, but Ari Lemmke, who ran the university server where the files were shared, named the folder Linux, and the name stuck. In 1992 Torvalds released the code under the GNU General Public License, which lets anyone use, change and share it as long as their versions stay open too; he later called this the best thing he ever did. Today thousands of developers around the world work on the kernel, and Linux also runs every one of the world's 500 fastest supercomputers.

Türkçe oku
Helsinki'de okuyan 21 yaşındaki Linus Torvalds, 25 Ağustos 1991'de ücretsiz bir işletim sistemi yazdığını internette duyurdu ve buna “sadece bir hobi” dedi. Kodu herkes inceleyip geliştirebilsin diye paylaştı. Gönüllüler ve şirketlerle büyüyen Linux bugün internetin büyük bölümünü ve bütün Android telefonları çalıştırıyor.
comp.os.minix, 25 Ağustos 1991

Torvalds duyurusunu comp.os.minix tartışma grubunda yaptı. Grubun konusu, kendi bilgisayarında da kullandığı, öğretim amaçlı küçük bir işletim sistemi olan MINIX'ti. Torvalds, projesinin “büyük ve profesyonel” olmayacağını da eklemişti. Linux aslında bir çekirdektir, yani işlemciyi, belleği ve donanımı paylaştırarak öteki programların çalışmasını sağlayan temel parça. Torvalds önce ona Freax adını vermişti; ama dosyaların paylaşıldığı üniversite sunucusunu yöneten Ari Lemmke klasörün adını Linux koydu ve bu ad tuttu. Torvalds 1992'de kodu GNU Genel Kamu Lisansı'yla yayımladı. Bu lisans, değiştirilmiş sürümler de açık kalmak şartıyla herkesin kodu kullanmasına, değiştirmesine ve paylaşmasına izin verir; Torvalds sonradan bunun yaptığı en iyi şey olduğunu söyledi. Bugün dünyanın dört bir yanından binlerce geliştirici çekirdek üzerinde çalışıyor; Linux, dünyanın en hızlı 500 süper bilgisayarının da hepsinde çalışıyor.

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Designed at the MIT Instrumentation Laboratory and built by Raytheon, the computer was one of the first to use silicon chips (integrated circuits) and fitted into about 28 litres. Its memory was counted in “words” of 16 bits, or binary digits: 2,048 rewritable and 36,864 permanent. During Apollo 11's descent on 20 July 1969 it flashed 1202 and 1201 alarms: a radar left on in case the landing had to be abandoned was stealing processing time and overloading it. Its operating system, designed by J. Halcombe Laning, dropped less urgent jobs and restarted in a moment while the landing programs kept running, so Mission Control told the crew to carry on. The flight software was written by a team led by Margaret Hamilton, who received the Presidential Medal of Freedom in 2016. Its power was similar to that of the first home computers of the late 1970s.

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Sponge divers found the mechanism in 1901, a corroded lump among treasures from a Roman-era ship that sank off the Greek island of Antikythera around 70 to 60 BC. Its hand-turned bronze gears modelled the movements of the Sun and Moon, and it is called the oldest known analogue computer, a machine that calculates with moving parts rather than digits. The eclipse dial follows the Saros cycle: after 223 lunar months (new moon to new moon), about 18 years and 11 days, the Sun, Earth and Moon return to almost the same positions, so eclipses repeat in a similar pattern. Symbols in 51 of the dial's cells mark 38 lunar and 27 solar eclipses. Much of this was read only in the 2000s, when researchers including Mike Edmunds and Tony Freeth used X-ray scans to see inside the fragments. The front, which probably showed the planets, is largely lost.

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