Lorenzo Dalvit et al.
3PAP: From the beginning, TeleWeaver was designed to easily integrate applications that have been developed independently and run in different software environment. This component facilitates this integration, using Open Standards methods. An example would be the ability to integrate with an e‐government system via TeleWeaver using Web Services.
4. TeleWeaver as a product
In this section we discuss the strengths and weaknesses of restrictive, permissive and hybrid licences, commonly used for open‐source software. Key issues to consider are compatibility and reciprocity. As noted by( Fitzgerald 2006), restrictive licences( such as GPL) are often used as a guarantee to possible contributors that the code will not be used for commercial ends. Two dimensions of restrictive licences are the requirement to redistribute modified version under the same licence and restrictions to mingling software with different licences( compatibility). Subsequent versions of the GPL seek to address particularly the compatibility issues but are still reciprocal. A project that bundles together software with different licences needs to work across platforms and intends to operate in a commercial environment, such as TeleWeaver, requires a more permissive licence.
Permissive licences( such as BSD) allow greater freedom to the user. This includes freedom to modify and redistribute the software for commercial gain. Permissive licences make it easier to build a community of contributors, who can benefit from signalling, for instance( Fitzgerald 2006). An example of an open‐source middleware project with a permissive licence is OSGi, which is a core part of TeleWeaver. OSGi is a standard implemented by several vendors. The most commonly used implementations are Eclipse OSGi and Apache Felix( open source projects). They are available under the Eclipse Public Licence and Apache Software Licence, respectively. A third common implementation, Knoplerfish OSGi created by a non‐profit organisation is available under the BSD licence. None of the three licences( EPL, APL and BSD) prevents commercial use. OSGi, like TeleWeaver, is a platform that can be taken as it is and used to deploy, at run time, without any code modifications, third party programs with different licences. According to( Fitzgerald 2006) this describes“ embedded software”, for which permissive rather than reciprocal licensing seems more appropriate. However, the use of a permissive licence does not seem to adequately protect the interests of all stakeholder of the TeleWeaver ecosystem. A model is needed which prevents third parties from modifying, re‐branding and distributing the software commercially with no direct benefit to the initial developers.
The Eclipse Public Licence is particularly relevant to the current discussion, in terms of compatibility as well as reciprocity. An Equinox derivative, licensed under the EPL, is an integral component of TeleWeaver. The EPL is incompatible with a reciprocal GPL licence. However, while systems including EPL‐licensed components can be released under different licences, the EPL requires that derivatives are released under the same licence. The use of an EPL licence opens two interesting possibilities. On the one hand, TeleWeaver as a whole can be released under a commercial licence, provided that the original EPL licence is preserved for its modified Equinox component. On the other hand, TeleWeaver can be released as free software under certain conditions, and an EPL licence would prevent third parties from using it or its derivatives for commercial purposes. The combination of these two scenarios requires a hybrid model.
In the hybrid model context, permissive licences feature strongly in the open core philosophy. Open‐core refers to software for which different licences are used for different components and / or features. A core set of components or features is released under a reciprocal licence while additional features and services are sold commercially. This type of licence allows vendors to build a community of contributors around the core open source code while providing an upgrade path to drive community users to become commercial customers. The main challenges associated with this model are to maintain the balance between the core code and commercial extensions. Community users must not feel as“ second‐class citizens” from which valuable functionality is withheld. This aspect is particularly important for the deployment within marginalised communities, where managing a relationship of mutual benefit and respect is a key success factor. For this reason, a dual‐licensing model segmented by type of user seems more appropriate for TeleWeaver.
Dual licensing provides a clear distinction between the community‐oriented version of the project and the commercially oriented version of the project. Community users are happy that no features or functionality are being withheld from them, while commercial users are happy that they have all the benefits of a commercial relationship. Segregating the user base by user type makes it more difficult for a vendor to encourage a
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