Microsoft operates the Azure cloud platform and was the world’s most valuable public company in 1999.
Microsoft reached the top of the global market-capitalization rankings during the late-1990s technology boom, with its valuation peaking around the turn of the millennium. Its dominance in personal-computer operating systems and productivity software made it exceptionally valuable to investors.
Azure, Microsoft’s cloud-computing platform, launched in 2010 under the name Windows Azure and was renamed Microsoft Azure in 2014. It provides computing, storage, databases, networking, analytics, and artificial-intelligence services to organizations worldwide.
The 1999 ranking is historical, not a claim that Microsoft permanently held first place. Market-cap leaders change as share prices, profits, industries, and investor expectations change. Microsoft later returned to the top tier through cloud growth and its broad enterprise software ecosystem.