This chapter describes a general software-based approach to conducting online Web research through the development of a custom research tool. Specifically, the tool is an Internet Explorer-like Web browser that can be designed to deliver experimental treatments and to collect experimental data with great precision and flexibility. The purpose of the manuscript is to introduce this approach to Web-based research, and to discuss the most salient issues, techniques, and problems that are involved in the development and use of such a research instrument. Programming custom event handlers, for a preexisting software object called the WebBrowser Control, constitutes a major part of the research approach. Event handling techniques having to do with downloading and navigation, with browser interface emulation, and with window and session control are presented. Other relevant issues such as cache management, keyboard handling, and accessing HTML page elements through the Document Object Model are also presented.