Case study of a non open source licence: SCSL

Sun Microsystems has released some of its core software technologies under a new licence, the Sun Community Source License (SCSL). This is not an open source licence, but it tries to mimic some of the characteristics of open source licences. In fact, the documents where Sun explains and provides rationale for their licensing schema¹¹include the usual arguments in favor of open source licences (although applied to SCSL). However, our opinion is that the points missing (those that would made it really open source) cause, from a practical point of view, most of the advantages of open source software to not be applicable to software covered by SCSL.

Some of the most widely known problems (from an open source point of view) with SCSL are:

• All the code modifications have to be sent to Sun if they are to be distributed. And it is Sun who decides if this modifications are redistributable or not. It is not possible to create even `experimental' code forks, due to clauses covering compatibility tests which must be passed.
• Sun is in fact using two licences for its code. One of them, suitable for ``research and internal deployment'', requires no fee. But the other, for ``commercial deployment'', requires that a fee be paid to Sun. The exact amount of this fee is decided by Sun, who therefore has total control on the code developed by contributors.
• For open source developers, the licence is felt to be dangerous, because it `taints' them. If they agree to the SCSL and download Sun code, they are prevented from using that or similar technology with an open source licence.

Software developed under SCSL benefits from some characteristics similar to those of open source software (access to source code, some redistribution rights). However, it lacks the synergy found in open source projects¹², due to the limitations of access to source code, integration of fixes and improvements, and the restrictions on redistribution. From a strategic point of view, any company or development group which uses or builds on code covered by SCSL is giving Sun a great control on their development and even marketing plans, which is usually considered undesirable.

The open source community is already reacting to this licence with the launch of several projects aimed at recreating SCSL covered technology in a completely `clean room' environment (without using Sun source code). It is always possible to pay later for accessing the test suites and brand the open source product, or simply ignore that problem, and concentrate on making it as compatible as possible¹³. In general, for a commercial project, it will be much more convenient to use, for instance, GPL instead of SCSL. The resulting software will benefit from all the advantages which it could have with SCSL, but the developer will have full control of the development plan, the distribution policy, and the marketing path.

Footnotes

... schema¹¹

The interested reader could refer to the licence FAQ [16], which includes many links to the licence itself and its rationale. Our discussion in this subsection is mainly based on [17].

... projects¹²

See subsection 4.3 for a discussion on the advantages of the open source model.

... possible¹³

This is, for example, the philosophy behind the open source library Mesa, a clone of SGI OpenGL, completely compatible with it, but without the legal brand `OpenGL'. Mesa is now used within commercial and open source software without the official brand tag.