the software, and often the developer is also its most important user. This is also the case in typical OpenSource software development. In combination of the functions the researcher/developer seems to be most productive, as he or she may be interested both in the musical data, in the processes (shaping-by-implementing) and in the implementation (performance, maintenance, etc.). As a consequence software development methodology is typically secondary and the development process results in working prototypes or collections of small tools rather than easy to use integrated products.

The software packages Humdrum, Rubato® and OpenMusic, which are examined in this paper, show a common property to cope with this situation and to be useful for as many users as possible: They derive their main value in the hands of the user, by showing different kinds of flexibility, which enable the user of the software to develop new processes and thereby perform genuine new research without the need to consult a professional developer.

1.2 Kinds of Configuration

Flexibility of tools can be achieved by deploying the following kinds of configuration techniques:

Preferences:

In this most common kind of configuration the user specifies values that in the following affect the behaviour of the software. Changing the »preferences« of a program is a typical configuration activity, but also the actual setting of values that affect a computation can be seen as a configuration act. This kind of configuration is heavily used in Rubato.

Selection:

This kind of configuration deals with the mapping of functionality to tools and the restriction of functionality. A simple example is the mapping of file name suffixes to programs in the operating system, so when a user double clicks a file, the corresponding program is started and the file is opened as a document of that program. Another example of this type of configuration is the JRing system, where the musicologist configures the system by defining, which functionalities he or she wants to use in the next JRing session. The JRing system on the other hand maps functionalities, such as search functions to available tools (Humdrum tools or other plug-ins, see Kornstädt (2002)).

Combination:

This kind of configuration is functionality-based. The user is offered handles (components) to the functionality of the system and can flexibly combine and control the data flow between them. Well-known visual programming based configuration systems are MAX and OpenMusic. Similarly interpreters give access to (exported) functionality of the application through programming in a scripting language. This kind of configuration is available in each of the examined software packages.