A big company's network produces millions of alerts a day, from firewalls, servers, routers and apps that do not talk to each other. ArcSight collected them all in one place and looked for the patterns that meant an attack. Its customers ran security command centers built around its screens. In February 2008, the Cupertino company went public as the financial crisis was starting, one of the few tech IPOs that year.

Wahoo Becomes ArcSight

The company was incorporated in May 2000 as Wahoo Technologies and renamed ArcSight in 2001. Co-founder Hugh Njemanze, a veteran of the search company Verity, became its chief technology officer. Robert Shaw became CEO in August 2001. ArcSight sold its first product, ArcSight ESM, in June 2002. The bet was that companies would buy one console to make sense of all their security data. Revenue grew from $32.8 million in fiscal 2005 to $69.8 million in fiscal 2007.

HP Takes Aim

ArcSight priced its IPO at $9 a share in February 2008 and listed on Nasdaq as ARST. Compliance rules and rising attacks kept sales growing through the recession. In September 2010 HP made a tender offer for ArcSight at $43.50 a share in cash, about $1.5 billion. The deal closed in October 2010. The ArcSight product later passed to Micro Focus and then to OpenText.

Cover: Salisbury Cathedral from the Meadows: the Rainbow, David Lucas. Art Institute of Chicago, public domain. Chosen for a rainbow arcing over a cathedral (an arc in sight).