European IT industry is certainly behind in terms of scale and penetration of global markets (the reasons are explained here in other comments, including fragmentation of the EU market and harder access to VC money), but I don't think it is behind in software engineering (especially considering numerous offices of American giants and EU aquisitions like Skype) and European companies can easily dominate on the local markets. All mentioned companies are quite successful and visible in EU (e.g. check the revenue of Zalando). And of course there are many other, classic software companies like SAP, TomTom, HERE etc.