The European Court of Justice has decided you cannot protect by copyright the functionality (way of working) of a computer program. So, assuming there is nothing in a computer program which is (or was) truly new – which might be protected by patent law – you may create your own program to copy what any other computer program does, so long as you write your own code.
It means that small startups in Europe will have less to worry about if their IT needs include functionality that somebody else’s pre-existing software has already made available. But the cautious and prudent ones will still be taking advice from an Intellectual Property expert to avoid falling foul of somebody’s patent. There’s a general tendency against patent protection for software in European Law. However, it’s the exact opposite in the USA where patent protection is much more freely granted, (It is then used as some kind of commercial legal warfare by the big players, who see it as a price they need to pay to be taken seriously. Or so I am told.)