Copying functions of computer program is not copyright infringement

That's supposed to be how the law always worked, and Pumphrey J said as much in his judgment in Navitaire v easyJet [2004] EWHC 1725 (Ch) (30 July 2004).  Advocate General Bot has now largely endorsed this approach in his opinion in Case C-406/10, SAS Institute v World Programming, a reference from the High Court (Arnold J, who posed eight very detailed questions) which has provided an invaluable and rather overdue opportunity for an explanation of how the earliest European Community effort in the field of copyright, the software directive, works."The functionalities of a computer program and the programming language are not eligible, as such, for copyright protection," he said. But the functionality of the program might be a substantial part of the copyright work, and it's a matter for the High Court to decide whether that's the case.

The program in suit emulates the software environment created by SAS, allowing programs written to operate in that environment to operate without it, using a much cheaper alternative. The software directive distinguishes copyright purposes between "ideas and principles which underlie any element of a computer program, including those which underlie its interfaces" and the expression of those ideas. Given the nature of the software in this case it would be hard to imagine a case which involved more "idea".

Advocate General Bot said that the possible workings of a computer program and the language used to create it is not in itself copyrightable because they constitute ideas without "concrete expression". Ideas on their own are not copyrightable.

The AG defined the functionality of a computer program as "the set of possibilities offered by a computer system, the actions specific to that program," going on:

In other words, the functionality of a computer program is the service which the user expects from it. In my view, the functionalities of a computer program cannot, as such, form the object of copyright protection under Article 1(1) of Directive 91/250. 

... Where a programmer decides to develop a computer program for airline ticket reservations, that software will contain a multitude of functionalities needed to make a booking. The computer program will have to be able, in turn, to find the flight requested by the user, check availability, book the seat, register the user’s details, take online payment details and, finally, edit the user’s electronic ticket. All of those functionalities, those actions, are dictated by a specific and limited purpose. In this, therefore, they are similar to an idea. It is therefore legitimate for computer programs to exist which offer the same functionalities.

There are, however, many means of achieving the concrete expression of those functionalities and it is those means which will be eligible for copyright protection. ... [C]reativity, skill and inventiveness manifest themselves in the way in which the program is drawn up, in its writing. The programmer uses formulae, algorithms which, as such, are excluded from copyright protection because they are the equivalent of the words by which the poet or the novelist creates his work of literature. However, the way in which all of these elements are arranged, like the style in which the computer program is written, will be likely to reflect the author’s own intellectual creation and therefore be eligible for protection.

Remarking that this was consistent with  the express purpose of the Directive, he went on:

To accept that a functionality of a computer program can be protected as such would amount to making it possible to monopolise ideas, to the detriment of technological progress and industrial development.

But then, in almost the next paragraph, he said:

In my view, as is the case with other works that may be protected by copyright, the fact of reproducing a substantial part of the expression of the functionalities of a computer program may constitute an infringement of copyright.

The distinction between ideas and expression is necessarily very nuanced, and reproducing the source code that expresses the functions of a computer program could infringe copyright. The Infopaq judgment (Case C‑5/08 [2009] ECR I-6569) tells us that parts of a work enjoy copyright protection, provided that they contain some of the elements which are the expression of the intellectual creation of the author of the work.  A computer program must be regarded as a literary work in its own right, so "the same analysis must be adopted in relation to the elements that constitute the expression of its author’s own intellectual creation".

The question of infringement concerns whether the reproduction is of "a substantial part of the expression of the functionalities of a computer program". This analysis takes no account of the "nature and extent of the skill, judgment and labour expended in devising the functionality of a computer program". The way that computer programs are written will determine whether they are protected by copyright: that's a matter of the degree of originality in the writing of the program. So copying the functions of a program is not infringement, but copying the expression of those functions might well be, according to the Advocate General (and, in due course, probably according to the Court): and the task of drawing the line, as it had to be, is left to the referring court. I wonder whether Arnold J feels he's got value for the effort he put in to posing the questions in the first place?