The idea was rock-solid, the market was ready, the corporate culture was in place, and the company founders, by their own admission, were “maniacally focused” on their mission. That was seven years ago, when Pat House and Tom Siebel first launched Siebel Systems with 12 employees and “the worst address on the planet” in Palo Alto, Calif. Today, the idea is still rock-solid, the market is still very receptive, the corporate culture is assiduously adhered to and the founders are as maniacally focused on their mission as ever. And according to House, it is paying off, big time. Siebel Systems is now headquartered in San Mateo, boasts 6,200 employees in 130 offices around the world, and is a leading supplier of eBusiness application software. “It’s brain surgery,” House, Siebel’s co-founder and executive vice president, says seriously.…