<i>It must be tough writing code in Europe - computers only use decimal points, not decimal commas. And how do you make an international interface for money, when you never know how people will enter things?</i><p>I&#x27;m kind of confused as to why you&#x27;re confused, so bear with me if I oversimplify, but are you aware of the globalization settings in your OS? It determines the display and entry format of things like currency. Yes, one will have to mentally switch back and forth when writing a float in code (float i = 3.14159) and paying bills with online banking ($1.345,12 sent to my mortgage company, please). But for the most part, you set bankBalanceTextField.text = $12000.01 and let the OS handle properly displaying it to the user.<p>To put it another way, for the globalized&#x2F;localized applications I&#x27;ve worked on, I put a little effort into making sure it&#x27;s globalizable (not hard-coding strings, not making assumptions about currency formats, make sure display fields are set to pick up display settings from OS, etc.), let the OS handle putting commas and decimal points as appropriate, and haven&#x27;t had major complaints so far. No complaints, despite not having the faintest clue how currency is formatted in, say, Russia.