The 2nd International Forum on Biosecurity, held in Budapest, Hungary on March 30-April 2, 2008, represents the efforts of a number of individuals and organizations, over the last five years, to engage the international community of life scientists in addressing how to reduce the risk that the results of their work could be used for hostile purposes by terrorists and states. The participants who gathered in Budapest were already engaged in this challenging task, and, therefore, the focus of the meeting was on what had been accomplished and what challenges remained. There was no attempt to achieve consensus, since there exist real and important differences among those involved concerning the appropriate policies and actions to be undertaken. But there was a serious effort to identify a range of potential next steps, and also an effort to identify opportunities where international scientific organizations could make substantive contributions and offer their advice and expertise to policy discussions. The Forum’s presentations, discussions, and results are summarized in this book.