Event notification and stream input/output have been always regarded as two separate paradigms. There are, however, applications - especially in the realm of user interfaces and experiments - that could benefit from being able to receive or deliver data in either form. We present a unified approach to data transfer that facilitates conversion in between the two concepts, as well as a flexible technique for implementing arbitrary event notification in an object-oriented way. A unified Input/Output library that simplifies error handling and ensures correct opening and closing of streams rounds up the proposed extensions to an operating system.