W is a computer music software developed by Roger Dannenberg. It is based on object-oriented programming and is designed for real-time. In later years, his legacy has been collected from Aura.
Brief History – W was developed in the mid-nineties by Roger Dannenberg at the School of Computer Science at Carnegie Mellon University in Pittsburgh. Designed for real-time, W is configured as a work that gathers in a single environment the best, until then, had been created with other music software.
Goals – The intent of its author was to merge into a single software all the features developed in others. For this reason, in W, there are materials derived from the Object-Oriented Programming, the MIDI protocol, by software such as Max/Msp, Formula and CMU MIDI Toll-kit of the same Dannenberg. In addition to merging the best features of other software; W allow, at the same time, a modular approach to the development of other software
Real Time – To make it a tool with interesting performance, W is designed for real-time. To achieve this, the software has been developed realizing a particular architecture based on a concept of priority work. In W, then, there are three operational areas, each with a different response in terms of latency: high priority/low latency, medium priority/medium latency and low priority/high latency. The communication between different areas, where the data is calculated in arrive order, is done by sending messages, since there are no shared data in memory. A final feature is that each object used in W can belong to only one area and can not be shared by others. W was initially designed with a single priority area.
Running – Being based on objects, the main feature of this software is to be a work environment where interconnect objects, each dedicated to specific functions. W working at a higher level than objects, modules and pre-existing libraries, treated as unique and interconnected blocks that exchange messages. A peculiarity of W was also to be able to interface with a high number of other software.
Aura – From its early development, W was not affected by subsequent versions but has provided the basis for the development of new software that has preserved the features but in a new name. Aura, then, is the successor of W, also used with the SICIB system and Escamol.
For this topic I’ve read:
 Roger Dannenberg, Dean Rubine, Toward Modular, Portable, Real-Time Software, Proceedings of International Computer Music Conference, Hong Kong, 1996.