Autonomy Has Largest Market Share in Email Archiving, According to Leading Market Research Firm

New Report Shows Autonomy Leads the Market with 23.7% Market Share

CAMBRIDGE, England and SAN FRANCISCO, October 12, 2010 - Autonomy Corporation plc (LSE: AU. or AU.L), a global leader in
infrastructure software for the enterprise, today announced that Gartner,
Inc. has ranked Autonomy as the worldwide market share leader in email
archiving based on total software revenue for 2009(1).

According to Gartner's report titled "Market Trends: E-mail Archiving
Strong Growth Continues" Autonomy achieved growth of 18.1% from 2008 to 2009
and market share of 23.7% in 2009.

Regarding the prospects for the email archiving market, Gartner states,
"The e-mail archiving software market saw 13.2% year-over-year growth in
2009. Although this is down from the 2008 growth rate of 25.7%, e-mail
archiving is still among the fastest-growing segments of the software market.
While the economic recovery and the success of service providers will impact
future growth, hosted solutions and improved offerings from the large
on-premises e-mail archiving software vendors should help boost growth of
23.0% through 2014."

Autonomy's comprehensive archiving platform, Autonomy Consolidated
Archive, is a modular, secure, and integrated platform that enables customers
to leverage the same market-leading archiving technology via an on-premise,
cloud-based, hybrid, or appliance based approach. The company's private
cloud-based archiving offering continues to generate impressive growth, and
recently passed the milestone of 17 Petabytes of data under management.

"We believe Autonomy's unique meaning-based approach to email archiving
continues to drive our impressive gains in market share," said Mike Sullivan,
CEO of Autonomy Protect, Enterprise Markets. "Autonomy's ability to
automatically identify the concepts and patters within the millions of
emails, audio, and video files that flow through a company each day enables
customers to appropriately archive and govern their content. By combining
these capabilities with Autonomy's highly secure and scalable private cloud,
we provide businesses with an unmatched platform from which to drive a range
of capabilities, including early case assessment, eDiscovery, legal hold,
records management, and multichannel marketing applications."

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, Deutsche Bank, DLA Piper, Ericsson,
FedEx, Ford, GlaxoSmithKline, Lloyds Banking Group, NASA, Nestlé, 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.

(1) Gartner, "Market Trends: E-mail Archiving Strong Growth Continues,"
by Sheila Childs and Alan Dayley, October 6, 2010

    Autonomy Editorial Contacts:
    Randy Cairns                     Louise Kehoe
    Autonomy (US)                    Ogilvy PR (US)
    +1-408-953-7111                  +1-415-677-2739
    Randy.cairns@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

Randy Cairns of Autonomy (US), +1-408-953-7111, Randy.cairns at autonomy.com; or Louise Kehoe of Ogilvy PR (US), +1-415-677-2739, louise.kehoe at ogilvypr.com; or Edward Bridges of Financial Dynamics (UK), +44-207-831-3113, edward.bridges at fd.com; or David Vindel of The Red Consultancy (UK), +44-207-025-6529, david.vindel at redconsultancy.com