The Boom in Enterprise I.P.O.'s While the impending giant public offering of Facebook gets most of the attention, enterprise technology companies keep attracting the money. On Friday, Proofpoint, a maker of corporate security software, began trading at $16.85 a share, 30 percent above its initial public offering price of $13. The stock was expected to price in the $10 to $12 a share range. Another company, the network software maker Infoblox, opened at $22.57, about 40 percent above its $16 IPO price. Infoblox had an expected initial public stock offering price of $12 to $14. On Thursday, Splunk, a data analysis company, had its debut. It closed at $35.48 a share, up 109 percent from an IPO price of $17. Splunk initially expected to price at $8 to $10, before that range was increased to $11 to $13. You may not have heard of Proofpoint, Infoblox or Splunk, and that may be the point: as we have written before, the low-profile companies that sell to businesses generally perform better than the companies that count on the loyalty of a fickle public for revenues. The game maker Zynga is flat from its December opening, while the corporate collaboration software maker Jive Software is up 70 percent over about the same period. A security company named Impervia is up 67 percent since its initial offering in November; Groupon, which came out a few weeks later, is off 56 percent. Many of the consumer companies have much larger market capitalizations than the enterprise companies, so one-to-one comparisons can deceive. Even after their initial pops, all three of this week's enterprise initial offerings will together have a market capitalization less than 10 percent of the $100 billion that Facebook is expected to garner next month. A somewhat larger enterprise company, Palo Alto Networks, is expected to go out next week. The biggest enterprise I.P.O. of the year, among start-ups, will probably be Workday, some time in the summer. Even these will be dwarfed by Facebook. That doesn't matter to an investor who got in early on an enterprise stock, however. Upside is upside. There are probably 10 more big tech initial public offerings coming this year, said John Connors, a partner at Ignition Partners in Seattle, and an investor and board member in Splunk. He cited ServiceNow, which automates corporate information technology processes; INRIX, a provider of traffic information; and Tableau, an analytics and business intelligence providerbased in Seattle. "The last 10 years have been consumer tech successes, companies like Google, and Yahoo compared with its opening price, or Amazon and Apple," Mr. Connors said. Now a lot of the approach to computing from open source is finding its way to reforming business, and that market is enormous. Enterprise companies tend to be attacking big, established markets where revenues are dependable. Online consumer companies are big and flashy, but they generally stake out new territory that is harder to value. The hype can easily outrun the real revenues.