A number of taxonomies to classify and categorize software visualization systems have been proposed in the past. Most notable are those presented by Price [1993] and Roman [1993]. While these taxonomies are an accurate representation of software visualization issues, they are somewhat skewed with respect to current research areas on software visualization. We revisit this important work and propose a number of realignments with respect to addressing the software engineering tasks of large-scale development and maintenance. We propose a framework to emphasize the general tasks of understanding and analysis during development and maintenance of large-scale software systems. Five dimensions relating to the what, where, how, who, and why of software visualization make up this framework. The focus of this work is not so much as to classify software visualization system, but to point out the need for matching the method with the task. Lastly, a number of software visualization systems are examined under our framework to highlight the particular problems each addresses.