The 10 Biggest Tech Companies You've Never Heard Of

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: about $2.8 billion in estimated revenue

Headquarters: New York, N.Y.

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.

Its 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 serves a very specific business niche, like dairies or footwear companies.

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 and maintain it. It specializes in complex stuff like Cisco networking and virtualization tech.

Its 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: About $400 million in estimated revenue

Headquarters: Dallas, Tex.

CEO: Lance Crosby

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

IBM and EMC are reportedly 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 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, the software that powers cash registers and other terminals businesses use to take money. It's got over 55,000 customers.

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 cloud space on its own data centers, too.

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

Intelligent Software Solutions: about $166 million in estimated revenue

Headquarters: Colorado Springs, Colo.

CEO: Jay Jesse

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

Urban Science: about $126 million

Headquarters: Detroit, Mich.

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, math-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.) Anderson has been its leader for 35 years.

Ahead: about $125 million estimated revenue

Headquarters: Chicago, Ill.

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 centers.

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