RTI worked with the Centers for Disease Control and Prevention (CDC) to convene a consultation with experts on the use of the Internet and new media to deliver HIV prevention messaging to men who have sex with men (MSM). Experts participated in discussions to examine the strengths and weaknesses of specific channels, technologies, and Web sites for delivering HIV prevention messages and how the issues raised could inform the development of electronic materials to educate and support choices for different risk reduction strategies (Lewis, et al. 2011). The experts strongly recommended developing an interactive Web-based tool to inform, educate, and support MSM choices for different risk reduction strategies. So, the purpose of this project was to develop content and messages, conduct extensive formative research, and design and develop a tailored, Internet-based HIV-prevention decision-support tool. Although the original intent was to develop the tool specifically for MSM, the audience was later expanded to include all individuals seeking information about HIV risk reduction, including heterosexual men and women and transgender people.