Ireland became home to one of Microsoft's international production facilities in 1985, and on November 20 Microsoft released its first retail version of Microsoft Windows (Windows 1.0), originally a graphical extension for its MS-DOS operating system. In August, Microsoft and IBM partnered in the development of a different operating system called OS/2. OS/2 was marketed in connection with a new hardware design proprietary to IBM, the PS/2. On February 16, 1986, Microsoft relocated their headquarters to a corporate office campus in Redmond, Washington. Around one month later, on March 13, the company went public with an IPO, raising US$61 million at US$21.00 per share. By the end of the trading day, the price had risen to US$28.00. In 1987, Microsoft eventually released their first version of OS/2 to OEMs. By then the company was the world's largest producer of software for personal computers—ahead of former leader Lotus Development—and published the three most-popular Macintosh business applications. That year the company purchased Forethought, the developer of PowerPoint and Microsoft's first major software acquisition on the 30th July 1987.