The decentralized nature of collaborations between objects in object-oriented software makes it diffic ult to understand the implementations of user-observabl e program features and their respective interdependencies. As feature-centric program under standing and modification are essential during software maintenance and evolution, this situation needs to change. In this paper, we present Featureo us, an integrated development environment built on top of the NetBeans IDE that facilitates feature-centric analysis of object-oriented software. Our integrate d development environment encompasses a lightweight feature location mechanism, a number of reusable analytical views, and necessary APIs for supporting future extensions. The base of the integ rated development environment is a conceptual framework comprising of three complementary dimensi ons of comprehension: perspective, abstraction and granularity. Together, these dimensions allow t he analyst to focus the analysis at the right mode of comprehension during software evolution. We demonst rate applicability of our integrated development environment by conducting a case study of change adoption using the JHotDraw SVG .