Autonomy One of the 10 Fastest-Growing Software Companies in the Software Magazine 500

Autonomy Named to Software Magazine's Annual Ranking for the Eleventh Consecutive Year

CAMBRIDGE, England, and SAN FRANCISCO, October 7, 2010 - Autonomy Corporation plc (LSE: AU. or AU.L), a global leader in
infrastructure software for the enterprise, today announced that Software
Magazine named Autonomy one of the 10 fastest-growing companies in the US$100
million to US$1 billion revenue category, as part of the publication's annual
ranking of the world's 500 largest software and services companies. Autonomy
generated total revenue of US$739.7 million and an exceptional 47% growth
rate in 2009.

The Software 500 is a revenue-based ranking of the world's largest
software and services suppliers targeting medium to large enterprises, their
IT professionals, software developers and business managers involved in
software and services purchasing. The ranking is based on total worldwide
software and services revenue for 2009. This includes revenues from software
licenses, maintenance and support, training and software-related services and
consulting. The Software 500 is currently featured on the publication's web
site, www.softwaremag.com.

"The growth of unstructured information — in the form of email, video,
audio, web, and social media, and other content — knows no boundaries," said
Stouffer Egan, CEO of Autonomy - US. "Autonomy's phenomenal growth is due to
the fact that we uniquely understand the meaning within this human friendly
information, and we capitalize on this powerful differentiator by providing
our global customer base with a comprehensive platform to power, promote, and
protect their business."

About Digital Software Magazine, the Software Decision Journal, and
Softwaremag.com

Digital Software Magazine, the Software Decision Journal, has been a
brand name in the high-tech industry for 30 years. Softwaremag.com, its Web
counterpart, is the online catalog to enterprise software and the home of the
Software 500 ranking of the world's largest software and services companies.
Software Magazine and Softwaremag.com are owned and operated by King Content
Co.

About Autonomy

Autonomy Corporation plc (LSE: AU. or AU.L), a global leader in
infrastructure software for the enterprise, spearheads the Meaning Based
Computing movement. IDC recently recognized Autonomy as having the largest
market share and fastest growth in the worldwide search and discovery market.
Autonomy's technology allows computers to harness the full richness of human
information, forming a conceptual and contextual understanding of any piece
of electronic data, including unstructured information, such as text, email,
web pages, voice, or video. Autonomy's software powers the full spectrum of
mission-critical enterprise applications including pan-enterprise search,
customer interaction solutions, information governance, end-to-end
eDiscovery, records management, archiving, business process management, web
content management, web optimization, rich media management and video and
audio analysis.

Autonomy's customer base is comprised of more than 20,000 global
companies, law firms and federal agencies including: AOL, BAE Systems, BBC,
Bloomberg, Boeing, Citigroup, Coca Cola, Daimler AG, Deutsche Bank, DLA
Piper, Ericsson, FedEx, Ford, GlaxoSmithKline, Lloyds TSB, NASA, Nestle, the
New York Stock Exchange, Reuters, Shell, Tesco, T-Mobile, the U.S. Department
of Energy, the U.S. Department of Homeland Security and the U.S. Securities
and Exchange Commission. More than 400 companies OEM Autonomy technology,
including Symantec, Citrix, HP, Novell, Oracle, Sybase and TIBCO. The company
has offices worldwide. Please visit www.autonomy.com to find out more.

Autonomy and the Autonomy logo are registered trademarks or trademarks of
Autonomy Corporation plc. All other trademarks are the property of their
respective owners.

    Autonomy Editorial Contacts:

    Zoe Welch                     Louise Kehoe
    Autonomy (US)                 Ogilvy PR (US)
    +1-415-625-1480               +1-415-677-2739
    zoe.welch@autonomy.com        louise.kehoe@ogilvypr.com

    Edward Bridges                David Vindel
    Financial Dynamics (UK)       The Red Consultancy (UK)
    +44-207-831-3113              +44-207-025-6529
    edward.bridges@fd.com         david.vindel@redconsultancy.com

    Software 500 Editorial Contact:
    Tracy Kunichika
    Software 500 Project Leader
    Tracyk@softwaremag.com

Zoe Welch of Autonomy (US), +1-415-625-1480, zoe.welch at autonomy.com; or Edward Bridges of Financial Dynamics (UK), +44-207-831-3113, edward.bridges at fd.com, or Louise Kehoe of Ogilvy PR (US), +1-415-677-2739, louise.kehoe at ogilvypr.com, or David Vindel of The Red Consultancy (UK), +44-207-025-6529, david.vindel at redconsultancy.com, all for Autonomy; or Tracy Kunichika, Software 500 Project Leader, Tracyk at softwaremag.com