Gateway computing environments face several challenges in providing robust, scalable, and sustainable capabilities to a wide range of users. Principles of encapsulation and cohesion have been applied in emerging trends of application framework development, where modular designs and abstraction layers allow these systems to remain flexible and agile as requirements evolve over time. Orbiter Commander is a modular and extensible application framework that leverages the Orbiter Federation Service Oriented Architecture to deliver fast and secure capabilities in an Eclipse RCP desktop application. Commander provides suites of modules that can be seamlessly delivered to end users on multiple platforms, enabling rapid component development through a flexible design and well-defined extension points. This paper presents our collaboration with the Spallation Neutron Source Neutron Experiment and Theory Hub (NExTHUB) and the Solenoidal Tracker at the at the RHIC (STAR) experiment, two suites of capabilities tailored to serve the needs of users at Oak Ridge National Laboratory and Brookhaven National Laboratory.