One of the most brilliant logos in the world, a rotationally symmetric chain ambigram, designed by computer science professor Vaughan Pratt.
Sun originally was the logo for the Stanford University Network. In 1982 when graduate student Andy Bechtolsheim built his 68000 Unix System for this university network, Vaughan Pratt designed the initial Sun Microsystems logo with the four interleaved copies of the word 'sun' by breaking the 's' into two components. The Sun name and logo became the name of the company Bechtolsheim and his fellow students set up.
The Sun logo is among some other logos one of the best ambigram logos, for more information, see: http://en.wikipedia.org/wiki/Ambigram#Other_logos