Additional information regarding forward-looking statements and risk factors is included in the company's periodic reports filed with the SEC. We caution listeners of the today's conference call not to place undue reliance on any forward-looking statement which speak only as of the date of this call. We undertake no obligation to update any forward-looking statements.I'd also like to mention that in addition to reporting financial results in accordance with generally accepted accounting principles or GAAP, during our call we will discuss several non-GAAP financial measures, specifically adjusted EBITDA and free cash flow. Adjusted EBITDA excludes interest income and expense, income taxes, depreciation, amortization of acquired intangible assets, restructuring expense, impairment of long-lived assets, acquisition and other related expenses in stock-based compensation costs. Free cash flow excludes capital expenditures from cash flows from operating activities. A reconciliation of adjusted EBITDA to GAAP net income from continuing operations and our free cash flow to GAAP cash flows from operating activities are included in the press release we issued this afternoon. I am now pleased to turn the call over to Mercury's president and CEO, Mark Aslett. Mark Aslett Thanks, Bob. Good afternoon, everyone, and thanks for joining us. I'll begin with an update on our business for the first quarter, Bob will review the financials and discuss our guidance and then we'll open it up for your questions. Mercury continued to perform well in Q1. Revenue and GAAP EPS both exceeded the high end of our guidance range. Bookings and 12-month backlog were up 6% and 45% year-over-year respectively. Adjusted EBITDA for Q1 increased 13% year-over-year and was well above our guidance. Finally, operating cash flow grew to $9.4 million, an increase of 259% year-over-year. Looking at our defense business, total defense revenue, including ACS and Mercury Federal, was in line with our expectations of $37.7 million, down 7.6% from Q1 of last year. Our commercial business more than made up the difference, however, as revenue grew nearly 120% year-over-year to $14.4 million.
Defense bookings for the first quarter were up 9% year-over-year. Our book-to-bill in defense was 1.09, up substantially from Q1 of fiscal 2010. With 45% growth year-over-year in our 12-month backlog, Mercury's on track to deliver solid organic growth on the top and bottom lines in fiscal 2011.Our major defense bookings this quarter include an order for the Taiwan Patriot System through Raytheon, continued business on the Aegis platform through Lockheed Martin and additional orders for the ASIP airborne signals intelligence package with Northrop Grumman. Q1 bookings in our commercial business were roughly flat with Q1 last year. Although backlog-driven revenue from KLA-Tencor will be winding down during the year, Q1 was our fourth consecutive quarter of increased revenue from ASML. Overall, we still expect roughly flat revenue in commercial for fiscal 2011 as compared with FY10. In our defense business we focused mercury on key markets that continue to look promising in terms of DOD funding as well as foreign military sales. These include ISR, ballistic missile defense and electronic warfare. At the same time, we have and continue to position Mercury to succeed in the defense markets driven by budget constraints and procurement reform. We've evolved our business model to align with the needs of the primes in an increasingly challenging environment. At a macro level, the major change is that Mercury is transitioning to being a best-of-breed commercial item ISR subsystem company. This means getting involved in programs earlier with an eye toward winning services [and] engagements that will generate long-term, production-based revenue annuity streams through the sale of ISR subsystems to the primes. Read the rest of this transcript for free on seekingalpha.com