In the highly dynamic Web environment, resources are continuously created, changed, deleted, and moved, and Web applications that leverage third party resources face the challenge of keeping in step with ubiquitous change. In ResourceSync: A Modular Framework For Web-Based Resource Synchronization, Los Alamos scientists Herbert Van de Sompel and Martin Klein describe a system that has been developed to synchronize resources. The ResourceSync framework specifies various modular capabilities that a repository can support in order to allow third party systems to remain synchronized with its evolving resources. Available on Vimeo (http://vimeo.com/97922977) and YouTube (http://youtu.be/xMHwudwBYLk).