Increasingly abundant access to data and cheaper display technology costs are creating an exciting opportunity to create new information awareness tools that can present information calmly through peripheral and ambient interfaces. These tools offer the potential to help people better manage their attention and to avoid information overload. Different people, however, have distinct information needs, and customizing these systems is often difficult. Existing interfaces typically provide too coarse or too fine a granularity of customization, resulting in tools that are too rigid or too difficult to configure. We present an extensively customizable information awareness system, The Buzz, that supports end users, tinkerers, and developers at using, modifying, creating, and sharing powerful and flexible customizations. These customizations are powerful in the sense that the user can control abstract behaviors of the system, and flexible in the sense that the complexity of the customization can vary with the power needed to express it. We further chart the broader information awareness customization space through the lens of existing customizable information tools. Through this analysis, we show that this system provides more extensive customization capabilities than other customizable awareness applications, without requiring significant programming.