Java JCE Providers - What Does Clean Room Mean?

Question

I need to write a JCE provider. I found out that I need to use a realistic room for cleanrooms. Could you tell me what “implementation of a clean room” means in this context?

Answer 1

The implementation of a clean room means in this context that the code was written only from the description and specification, but not with access to potentially unpleasant code.

This is important because Sun's source code was previously licensed, which was incompatible with the GPL. After making sure that the code was not written without any access to such code, it is guaranteed that subsequently the Sun license will not be applied to the implementation of a clean room, and then again will be incompatible with the GPL license or any other restrictions.

In other words, this is a guarantee that the specified license will be retained.

Answer 2

Despite the name, most re-implementations are done in rooms with predominantly empty beer cans and pizza boxes. This speaks of past experience, you understand :-)

However, in the context of chip development, a clean room is one where small defects (like dust) can cause serious problems on a nanoscale scale. Thus, they are kept incredibly clean, with air scrubbers, protective suits (protecting the environment, not worn), etc.

By analogy, the development of cleanroom software is carried out without any access to deficiencies that can cause problems. In the case of open source software, this means a lack of access to an implementation that may be “corrupted” by an incompatible license. (This is not just the GPL, but it is usually cited because of its viral nature). However, this also applies to closed source reverse engineering projects, such as the creation of an IBM-compatible BIOS that opened the market for IBM clones back in the 80s.