Traditionally, interaction techniques for virtual reality applications are implemented in a proprietary way on specific target platforms, e. g., requiring specific hardware, physics or rendering libraries, which withholds reusability and portability. Though hardware abstraction layers for numerous devices are provided by multiple virtual reality libraries, they are usually tightly bound to a particular rendering environment. In this paper we introduce Viargo - a generic virtual reality interaction library, which serves as additional software layer that is independent from the application and its linked libraries, i. e., a once developed interaction technique, such as walking with a head-mounted display or multi-touch interaction, can be ported to different hard- or software environments with minimal code adaptation. We describe the underlying concepts and present examples on how to integrate Viargo in different graphics engines, thus extending proprietary graphics libraries with a few lines of code to easy-to-use virtual reality engines.