Siebel Systems, Inc. was an American software company founded in 1993 by Thomas M. Siebel and Patricia House, specializing in customer relationship management (CRM) software. It became a leader in CRM, offering enterprise-grade CRM solutions with extensive customization and integration capabilities. Oracle acquired Siebel Systems for $5.85 billion in 2006, and the Siebel CRM product is now part of Oracle's offerings, addressing complex business processes across sales, marketing, and customer service.