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|Headquarters||Herndon, Virginia, United States|
|Mike Corkery (CEO)|
|Products||Enterprise Software and Information solutions|
Deltek is an enterprise software and information solutions provider for professional services firms and government contractors.
In 1983, the company was founded as Deltek Systems, Inc. by Donald deLaski and his son Kenneth.
From the beginning, Deltek's niche in the software industry is its focus on developing software for use by companies that are project focused, such as government contractors (who must, under U.S. government procurement law, track costs by individual contract, and in some cases by task order or line item). Later, Deltek expanded its marketing focus towards Architect/Engineer and consulting firms (who must also be able to account for costs by project). From inception the company has been located in the Washington DC area.
In 1984, Deltek delivered its first system, originally named Deltek Government Contracting System, but later renamed Deltek System1, and now known as Deltek GCS Premier.
In 1993, Deltek began developing its next generation of project accounting solutions, which eventually led to the development of Costpoint in 1994, which at the time was a contemporary 4GL client/server project focused ERP. Costpoint allowed Deltek to expand its vertical footprint and eventually became its flagship product.
In 1997, Deltek began trading publicly and bought several other companies and products. It was taken private again in 2002.
In March, 2004, Deltek introduced the first comprehensive software management tool to help government contractors better compete, win and retain government contracts.
In April 2004, Beers & Cutler (now Baker Tilly http://www.bakertilly.com/) and Deltek Systems, Inc. formed a strategic alliance, through which Beers & Cutler would deliver consulting services supporting the latest Deltek solutions and applications.
In 2005, the company was recapitalized by an organization called the New Mountain Capital, based in New York, NY.
In March 2006, Deltek acquired WST, Inc. (“Welcom”). Welcom, (WST Inc) was a company formed in the 1980s who were a global leader in earned value management (EVM) and project portfolio management (PPM) solutions (project management software). Welcom products included Cobra, Open Plan, Opera and Opmist. In 1990, Welcom claimed to have 7,000 Open Plan users worldwide - 4,000 of them in the US, mainly in the defence and aerospace industries and supported Unix, Macintosh and personal computer versions. The software was highly customisable using dBASE or FoxBASE products.
In May 2007, Deltek acquired WST Pacific Pty Ltd. (“WSTP”), a provider of earned value management (“EVM”) solutions based in Australia, and previously a development partner of Welcom, and incorporated their Open Plan (enterprise project scheduling software), Cobra (cost and earned value management software) and WelcomHome (Web-based project collaboration software) into their product range.
In 2010, Deltek acquired European competitor Maconomy and government market analysis company INPUT Inc.
On April 1, 2011, Deltek acquired another government market analysis company, FedSources, Inc, FedSources Consulting and Washington Management Group (WMG).
In 2013, Deltek acquired Project Portfolio and Analytics company Acumen. In February of the same year, Deltek named Mike Corkery CEO. In November of the same year Deltek acquired another competitor Centurion Research.
In 2015, Deltek acquired HRsmart based in Dallas, Texas.
In 2016, Deltek acquired Union Square Software based in Nottingham, UK. 
Deltek’s global operations are directed from its headquarters in Herndon, Virginia, USA. It also conducts business from three other US-based offices located in Portland, OR, Woburn, MA, and Austin, TX.
Deltek current portfolio of products and solutions is focused upon two market segments - professional services firms and government contractors.
Solutions for Professional Services Firms:
• Deltek Vision - manages critical business functions such as client management, sales and marketing, resource and project management, time and expense capture, accounting, and billing.
• Deltek Maconomy - ERP solution that manages and streamlines the key business processes of Professional Services organizations.
• Deltek People Planner - resource planning and resource management solution for project-oriented organizations.
Solutions for Government Contractors:
• Deltek Costpoint - enterprise management software solution that tracks, manages and reports on every aspect of a project business.
• Deltek First GovCon Essentials - accounting and project accounting solution in Cloud for small and medium-sized businesses who sell services to the U.S. government.
• Deltek Integrated Program Management (IPM) - suite of project management applications that adhere to ANSI 748 compliance.
• GovWin IQ - Federal, State and local market intelligence.
• GovWin CRM – business development and capture software.
• GovWin.com – teaming and software solutions to help organizations find, manage and win government business.
Deltek has made a corporate commitment to minimize its impact on the environment. All work areas in its Herndon, Virginia, headquarters have direct access to natural light, minimizing the need for artificial light throughout the property. In addition, 75% of the lights are controlled by sensors so lights are only used on demand. Most of the construction materials used were sourced from landfills and 20% of the manufactured materials were sourced from production locations within a 500-mile radius of the new headquarters. The sustainability of the new headquarters is allowing Deltek to target a LEED silver certification.
- INPUT Inc.
- FedSources, Inc.
- FedSources Consulting
- Washington Management Group (WMG)
- Welcom (WST Inc)
- WST Pacific
- Acumen 
- Centurion Research Solutions
- Sohnar (Traffic LIVE)
- Axium (company)
- "Deltek Launches First Comprehensive Business Development Solution For Government Contracting Market".
- "Beers & Cutler and Deltek Systems Inc. Form Strategic Alliance".
- "Form 10-K". Wikinvest.com. Retrieved 2013-02-07.
- Griffe Witte (2006-05-10). "Outsider To Become Chairman Of Deltek". washingtonpost.com. Retrieved 2008-06-13.
- "A Software Insiders Point of View: IPO Watch: Deltek Files S-1". softwareinsider.blogspot.com. 2007-05-09. Retrieved 2008-06-13.
- Deltek (2011-04-01). "Deltek Acquires FedSources and the Washington Management Group". deltek.com. Retrieved 2011-04-01.
- Deltek to be acquired by Thoma Bravo for $1.1 billion
- Software Equity Group's Client, Acumen PM, Acquired by Deltek
- Deltek Promotes Insider to CEO
- Deltek Acquires Centurion Research Solutions
- Deltek Acquires Sohnar and its Traffic LIVE Solution to Deliver Industry-Leading Project Management and Resource Planning to Marketing Agencies and other Professional Services Firms
- Deltek Acquires Axium to Extend Its Market Leadership in the Architecture and Engineering Industry
- Deltek Completes its Acquisition of HRsmart
- Deltek Acquires Union Square Software
- Deltek Acquires Acumen
- Deltek Buys Centurion Research to Bolster BD
- Deltek Acquires Sohnar and its Traffic LIVE Solution
- Deltek Completes its Acquisition of HRsmart