Large wikis such as Wikipedia attract large numbers of editors continuously editing content. It is difficult to observe what editing activity goes on at any given moment, what editing patterns can be observed, and which are the currently active editors and articles. We introduce the design and implementation of an information visualization tool for streaming data on recent changes in wikis that aims to address this difficulty, show examples of our visualizations from English Wikipedia, and present several patterns of editing activity that we can visually identify using our tool.