Siebel CRM Systems, Inc. was a software company mainly engaged in the design, development, marketing, and support of customer relationship management applications. The company was founded by Thomas Siebel and Patricia House in 1993. At first known chiefly for its sales force automation products, the company expanded into the broader CRM market. By the late 1990s, Siebel Systems was the leading CRM vendor, peaking at 45% market share in 2002.