Presentation of advanced content items is selectively suspended and/or activated so as to manage system resources. In some embodiments, plug-in code is selectively activated based on prioritization schemes and responsive to resource usage, user input, and/or other conditions. For example, plug-in code can be selectively suspended when the advanced content being presented by the plug-in code is not in view (for example, if it has been scrolled off the screen); when the advanced content is brought into view, for example as a result of scrolling, the plug-in code is reactivated as appropriate and the presentation of the advanced content resumes. State information for suspended plug-ins can be stored so that upon reactivation, plug-in code resumes operation substantially where it left off.