The 10 Biggest Tech Companies You've Never Heard Of

With all the talk about Dell going private so it can revamp itself without Wall Street on its back, we got curious.

Who are the biggest private enterprise companies? Better yet, who are the biggest private companies under the radar?

So we looked around. We examined at our own Digital 100 list of the most valuable private tech companies in the world. We scanned through the Forbes list of America’s Largest Private Companies. We looked at the Inc. 500 and the Silicon Valley Business Journal’s lists, too. (All used estimated revenue for 2011, the latest full-year data available.)

World Wide Technology: $4.1 billion

World Wide Technology: $4.1 billion in estimated revenue

Headquarters: St Louis, MO

CEO: James Kavanaugh

WWT is a 'systems integrator' which means tech consultant that helps companies roll out big enterprise projects like VMware software, secure networks, Bring Your Own Device software.

It's home to about 1,800 employees and was named one of the 100 best companies to work for thanks to generous profit sharing.

SHI International: $4.5 Billion

SHI International: $4.5 billion in estimated revenue

Headquarters: Somerset, N.J.

CEO: Thai Lee

SHI International (formerly known as Software House International) is an online marketplace where enterprises can buy tech like computers, printers, servers and so on. It also sells consulting services and cloud computing.

At $4.5 billion in revenue (according to a company's spokesperson) and with over 2,000 employees, SHI is the one of the largest minority and woman-run tech businesses in the nation.

Infor: $2.8 billion

Infor: about $2.8 billion in estimated revenue

Headquarters: New York

CEO: Charles Philips

Infor is has quietly become a huge enterprise app company, with around $3 billion in sales and an estimated valuation of $16.1 billion.

It's CEO knows software. He is ex-Oracle president Charles Philips. One of the reasons Infor stays under the radar is that it has grown by acquisitions, so it's like a collection of smaller software companies. Each of them serve very specific business niches, like dairies or footwear companies.

Zones: $1 Billion

Zones: about $1 billion in estimated revenue

Headquarters: Auburn, Wash.

CEO: Firoz Lalji

Zones is a 'value-added-reseller' meaning it sells computer hardware, software and equipment to businesses and then helps them install it and maintain it. It specialises in complex stuff like Cisco networking and virtualization tech.

It's CEO is an interesting guy. Uganda born Lalji was the founder of the retail store chain Kit Cameras which he sold in 1997 right before he took on the CEO job at Zones.

SoftLayer: $400 million

SoftLayer: About $400 million in estimated revenue

Headquarters: Dallas

CEO: Lance Crosby

SoftLayer is one of the largest privately held cloud-computing and Web-hosting service providers.

IBM and EMC are reportedly both in a battle to buy the company. It has a valuation of about $2.8 billion and brought in an estimated $400 million in 2012, up from $300+ million 2011.

PayPros: $214 million

PayPros: $214 million in estimated revenue

Headquarters: Newark, Calif.

CEO: Chuck Smith

PayPros (formerly called Payments Processing) is a company that sells payments processing software and point-of-sale software to businesses, the software that runs cash registers and all kind of other ways to take money. It's got over 55,000 customers.

Datapipe: $200 million

Datapipe: about $200 million in estimated revenues

Headquarters: Jersey City, N.J.

CEO: Robb Allen

Datapipe offers IT management services to companies using cloud computing. It works with Amazon's cloud and offers its own cloud in its own data centres, too.

Based on estimated revenues of $200 million in 2011, it has a valuation of about $2 billion.

Intelligent Software Solutions: $166 million

Intelligent Software Solutions: about $166 million in estimated revenue

Headquarters: Colorado Springs, Colo.

CEO: Jay Jesse

ISS offers big data software and visualisation/mapping software popular with government agencies like spies and the military.

Urban Science: $125 million

Urban Science: about $126 million

Headquarters: Detroit

CEO: Jim Anderson

Urban Science offers business analysis software for auto makers worldwide. It was founded in 1977 when Anderson was a professor at Wayne State University. He came up with a way for Cadillac to do sophisticated, maths-and-science-based marketing. It's sort of like 'Moneyball' for cars. (Yes, we're referring to the Brad Pitt movie about the Oakland A's.) And Anderson has been its leader for 35 years.

Ahead: $125.3 million

Ahead: about $125 million estimated revenue

Headquarters: Chicago

CEO: Daniel Adamany

Ahead is a tech service company that describes itself as 'a collective brain of technologists and consultants.' It helps enterprises deploy the latest, greatest tech for their networks and data centres.

More big companies growing like crazy

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