A trader watches screens at his desk at the Frankfurt stock exchange.

There are many big tech companies, such as Apple and Google, but which are the best to work for?

Let’s take a look at some of the best tech companies to work for, according to Glassdoor, a jobs and career community that offers the world an inside look at jobs and companies.

Courtesy guidewire

Guidewire

Company Rating: 4.4

CEO Approval: Marcus Ryu, 98 per cent

Global rank: 1

Guidewire Software, commonly just Guidewire, is a privately held American corporation based in San Mateo, California.

It offers core back-end software for property and casualty insurance carriers in the US and worldwide.

Facebook employees work in the design studio at the company's headquarters in Menlo Park, California.

Facebook

Company Rating: 4.3

CEO Approval: Mark Zuckerberg, 89 per cent

Global rank: 2

Facebook is an American multinational Internet corporation which runs the social networking website Facebook. After having been privately owned by Mark Zuckerberg and other founders, and the shared ownership having been contested, Facebook eventually filed for an initial public offering on February 1, 2012.

A page from the LinkedIn website is seen in Singapore.

LinkedIn

Company Rating: 4.1

CEO Approval: Jeff Weiner, 92 per cent

Global rank: 3

LinkedIn is a professional social networking website. Founded in December 2002 and launched in May 2003, it is mainly used for professional networking.

As of February 9, 2012, LinkedIn reports more than 150 million registered users in more than 200 countries and territories.

Mitre is based in Bedford, Massachusetts, and McLean, Virginia.

Mitre

Company Rating: 4.1

CEO Approval: Alfred Grasso, 92 per cent

Global rank: 4

The Mitre Corporation is an American not-for-profit organisation based in Bedford, Massachusetts, and McLean, Virginia.

It manages Federally Funded Research and Development Centers supporting the Department of Defence, the Federal Aviation Administration, the Internal Revenue Service, the Department of Veterans Affairs, the Department of Homeland Security, and the Administrative Office of the US Courts on behalf of the Federal Judiciary.

Google homepage logos are seen on a wall at the Google campus near Venice Beach in Los Angeles.

Google

Company Rating: 4.0

CEO Approval: Larry Page, 92 per cent

Global rank: 5

Google is an American multinational corporation which provides Internet-related products and services, including Internet search, cloud computing, software and advertising technologies.

Advertising revenues from AdWords generate almost all of the company’s profits.

CareerBuilder.com is the largest online employment website in the United States.

CareerBuilder

Company Rating: 4.0

CEO Approval: Matt Ferguson, 97 per cent

Global rank: 6

CareerBuilder.com, operated by CareerBuilder, is the largest online employment website in the United States, with more than 23 million unique visitors each month and a 34 per cent market share of help-wanted web sites in the United States.

CareerBuilder.com provides online career search services for more than 1,900 partners as of March 2008, including 140 newspapers and portals such as AOL and MSN. It was founded in 1994.

A spectator uses an iPad to record Gloria Coelho's Summer 2012/2013 collection during Sao Paulo Fashion Week.

Apple

Company Rating: 3.9

CEO Approval: Tim Cook, 96 per cent

Global rank: 7

Apple is an American multinational corporation that designs and sells consumer electronics, computer software, and personal computers.

The company’s best-known hardware products are the Macintosh line of computers, the iPod, the iPhone and the iPad.

Rackspace is an IT hosting company based in San Antonio, Texas.

Rackspace

Company Rating: 3.9

CEO Approval: A Lanham Napier, 84 per cent

Global rank: 8

Rackspace is an IT hosting company based in San Antonio, Texas. The company also has offices in Australia, the United Kingdom, The Netherlands and Hong Kong, and data centres operating in Texas, Illinois, Virginia, the United Kingdom and Hong Kong.

Salesforce.com CEO Marc Benioff speaks in Tokyo.

Salesforce.com

Company Rating: 3.9

CEO Approval: Marc Benioff, 88 per cent

Global rank: 9

Salesforce.com is a global enterprise software company headquartered in San Francisco, California, United States. Best known for its Customer Relationship Management product, through acquisitions Salesforce has expanded into the “social enterprise arena”.

It is a producer of automated test equipment and virtual instrumentation software.

National Instruments

Company Rating: 3.8

CEO Approval: James T Truchard, 100 per cent

Global rank: 10

National Instruments Corporation is an American company with international operation. Headquartered in Austin, Texas, it is a producer of automated test equipment and virtual instrumentation software.

Common applications include data acquisition, instrument control and machine vision.

Wayfair is a US-based multinational e-commerce company.

Wayfair

Company Rating: 3.8

CEO Approval: Niraj Shah, 96 per cent

Global rank: 11

Wayfair is a US-based multinational e-commerce company. The company began selling furniture online in 2002, and now sells many other home furnishings, luggage, toys, and pet items from over 5,000 brands.

Headquartered in Boston, Massachusetts, Wayfair also has warehouse and corporate locations elsewhere in the United States, and in Australia, Germany, Ireland, and the United Kingdom.

Citrix Systems is a multinational corporation founded in 1989.

Citrix Systems

Company Rating: 3.8

CEO Approval: Mark B Templeton, 92 per cent

Global rank: 12

Citrix Systems is a multinational corporation founded in 1989, that provides server and desktop virtualisation, networking, software-as-a-service, and cloud computing technologies, including Xen open source products.

Citrix currently services around 230,000 organisations worldwide and is based in Fort Lauderdale, Florida, in the South Florida metropolitan area, with subsidiary operations in California and Massachusetts, and additional development centers in Australia, India, and the United Kingdom.

A view of one of Qualcomm's numerous buildings located on its San Diego Campus.

Qualcomm

Company Rating: 3.8

CEO Approval: Paul E Jacobs, 89 per cent

Global rank: 13

Qualcomm is an American global telecommunications equipment corporation that designs, manufactures and markets digital wireless telecommunications products and services based on its code division multiple access technology and other technologies.

Headquartered in San Diego, California, US.

A booth of German company SAP during preparations at the CeBit computer fair in Hanover.

SAP America

Company Rating: 3.8

CEO Approval: Jim Hagemann Snabe and Bill McDermott, 85 per cent

Global rank: 14

SAP is a German multinational software corporation that makes enterprise software to manage business operations and customer relations.

Headquartered in Walldorf, Baden-Wurttemberg, with regional offices around the world, SAP is the market leader in enterprise application software.

NetApp is a proprietary computer storage and data management company.

NetApp

Company Rating: 3.7

CEO Approval: Tom Georgens, 100 per cent

Global rank: 15

NetApp, formerly Network Appliance, is a proprietary computer storage and data management company headquartered in Sunnyvale, California.

It is a member of the Nasdaq-100. It was ranked on the Fortune 500 for the first time in 2012.

Adobe CEO Shantanu Narayen in Las Vegas.

Adobe

Company Rating: 3.7

CEO Approval: Shantanu Narayen, 67 per cent

Global rank: 16

Adobe is an American multinational computer software company founded in 1982 and headquartered in San Jose, California, United States.

The company has historically focused upon the creation of multimedia and creativity software products, with a more-recent foray towards rich Internet application software development.

Morningstar is a financial data provider based in Chicago.

Morningstar

Company Rating: 3.6

CEO Approval: Joe Mansueto, 95 per cent

Global rank: 17

Morningstar is a financial data provider based in Chicago, Illinois, US. Morningstar provides data on more than 380,000 investment offerings, including stocks, mutual funds, and similar vehicles, along with real-time global market data on more than eight million equities, indexes, futures, options, commodities, and precious metals, in addition to foreign exchange and Treasury markets.

A woman takes a photo of ultrabooks at the Intel booth in Las Vegas.

Intel

Company Rating: 3.6

CEO Approval: Paul S Otellini, 94 per cent

Global rank: 18

Intel Corporation is an American multinational semiconductor chip maker corporation headquartered in Santa Clara, California, United States, and the world’s largest and highest valued semiconductor chip maker, based on revenue.

Groupon CEO Andrew Mason walks with his wife Jenny Gillespie outside the Nasdaq in New York.

Groupon

Company Rating: 3.6

CEO Approval: Andrew Mason, 78 per cent

Global rank: 19

Groupon is a deal-of-the-day website that features discounted gift certificates usable at local or national companies.

Groupon was launched in November 2008, and the first market for Groupon was Chicago, followed soon thereafter by Boston, New York City, and Toronto.

Intuit is an American software company that develops financial and tax preparation software.

Intuit

Company Rating: 3.6

CEO Approval: Brad Smith, 84 per cent

Global rank: 20

Intuit is an American software company that develops financial and tax preparation software and related services for small businesses, accountants and individuals.

It is incorporated in Delaware and headquartered in Mountain View, California.