Jumpshot-4 is a visualization program for the logfile format, SLOG-2, which provides a hierarchical structure to store a large number of drawable objects in a scalable and efficient way for visualization. SLOG-2's new scalable logfile format allows the display program to provide functionalities never before possible. Level-of-detail support through preview drawables provides high-level abstraction of the details without reading huge amounts of data into the graphical display engine. Jumpshot-4 allows seamless scrolling from the beginning to the end of the logfile at any zoom level. In addition, new functionalities are available, such as dragged-zoom, grasp and scroll, instant zoom in/out, easy vertical expansion of timelines, and cut and paste of timelines. A new search-and-scan facility is provided in order to locate hard-to-find objects in a very large logfile. Also, the histogram module based on user-selected duration provides a convenient and graphical way to analyze the statistics of a logfile (e.g., it enables easy detection of load imbalance among timelines). The new legend table makes manipulation of the different categories of objects easy. The new viewer also provides an integrated logfile convertor for all known SLOG-2 convertible trace formats, including CLOG, CLOG-2, RLOG, and UTE, and it conforms to the standard look and feel expected by most users.