[fpc-devel] regarding RTTI unit mail

Daniël Mantione daniel.mantione at freepascal.org
Sat Aug 28 22:31:33 CEST 2010

Op Sat, 28 Aug 2010, schreef Dimitri Smits:

> Hi,
> (just hate it when you send something after re-reading it a few times, and a minute later you know that there is something important you forgot to ask)
> Since objectnames and interfaces are cloned from Delphi everywhere in the fpc-rtl, I was wondering if this is legitimate use and not a copyright violation?
> ie: the "interface" is the same, the implementation is different (unless trivial).
> Is this, or is this not an issue?

The EU software directive says a few words about this matter:

"Protection in accordance with this Directive shall apply to the 
expression in any form of a computer program. Ideas and principles which 
underlie any element of a computer program, including those which underlie 
its interfaces, are not protected by copyright under this Directive."

In other words: It is okay to copy the interface, but not its expression.

Copyright is about creative decisions. For example the order in which 
procedures, variables are declared are creative decisions and thus part of 
the expression of an interface. If you make the same creative decisions as 
the original program, you violate copyright.

Generally safe is the clean room approach: Someone who doesn't know the 
Delphi source code implements it from documentation. This is 
internationally considered best practise and can avoid discussions wether 
it is a violation or not. If you happen to know the Delphi sources, you 
have to be carefull what you write.

The EU software directive allows us to develop FPC in a reasonably safe 
way, but the borders between independent implementation and copyright 
violation unfortunately is not black and white.


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