Presenter:   Katja Henttonen
Session: 2
Room: 2

Nowadays many digital devices, such as set-top boxes and mobile phones, provide an Application Programming
Interface (API), which allows power users to tailor the accompanying software. For example, one can make changes
to an unfit user interface to increase usability of a device or build custom extensions to introduce new features. There
are also communities which share such modifications and extensions as free or open source software (F/OSS). Even
layman (i.e. people who have no programming skills) can modify or extend the capabilities of their digital devices by
downloading and installing these ready-made software bundles. However, usability and a need for custom features
depend on personal preference and, therefore, many laymen would like to tailor the software by themselves.
Third-generation programming languages (3GLs) cannot be used to enable computer illiterate people to extent or
modify the software on their digital devices, not even with the most user-friendly API imaginable. However, it might
be possible for layman to program with Domain-Specific Modelling Languages. This article introduces a
revolutionary approach which enables laymen to become contributors in the F/OSS movement. The approach is
based on a combination of Domain-Specific Modelling and F/OSS development. Herein, we call it "Free or Open
Models" (F/OM) development. In F/OM, users share (a) visual models from which complete code generation is
possible and (b) complete modelling infrastructure for various application domains. Both models and the
infrastructure can be used, modified and extended freely. For the first time, even computer illiterate people can enjoy
the freedom of modifying software and sharing their improvements with others.