Charles Simonyi

Charles Simonyi
Simonyi in 2006
Born (1948-09-10) September 10, 1948
CitizenshipHungary
United States
Alma materUniversity of California, Berkeley (BS)
Stanford University (PhD)
OccupationSoftware architect
Known forHungarian notation, space tourism, intentional programming
Notable workMicrosoft Office
Spouse
Lisa Persdotter
(m. 2008)
Children2
Parents
RelativesSándor Simonyi-Semadam (great-grandfather)
Space career
Space Adventures tourist
Time in space
26d 14h 27m
MissionsSoyuz TMA-10/TMA-9, Soyuz TMA-14/TMA-13

Charles Simonyi (/sɪˈmni/; Hungarian: Simonyi Károly, pronounced [ˈʃimoɲi ˈkaːroj]; born September 10, 1948) is a Hungarian-American software architect, businessman, and space tourist. He led the development of Microsoft's first application software, including early versions of Microsoft Office, and later co-founded Intentional Software, a company focused on his concept of intentional programming. A former researcher at Xerox PARC, he helped pioneer graphical user interfaces and introduced object-oriented programming and Hungarian notation to Microsoft. Simonyi flew to space twice as a private citizen, becoming the fifth space tourist and the only one to pay for two separate trips to the International Space Station. As of January 2025, his net worth was estimated at US$7.5 billion.