Railway Markup Language

railML (Railway Markup Language) is a proprietary freeware XML Schema-based data exchange format for data interoperability of railway applications.

==Motivation== thumb|Advantage of a universal exchange format The growing number of computer applications modeling different aspects of railway operations, with different operators developing separate solutions parallelly, bore a chronic difficulty of connecting different railway IT applications. The exchange of data for operation concepts, slot management, simulation or infrastructure planning, etc. was possible either by hand or with a lot of special developed interfaces with loss of time and cost problems for railway companies. If there are n applications that are supposed to exchange data, with a special interface for each pair of programs respectively, \frac{n\cdot(n-1)}{2} interfaces are required—only one, if n=2, but 10, if n=5—increasing the complexity above average.