PropXX provides a property/configuration mechanism for C++ applications. Properties can be defined in files similar to but more flexible than Java properties. Property files are defined in a type-safe, modular way and offer the full expressiveness of the Lua scripting language. The design of PropXX combines flexibility with high-performance for the C++ code which accesses property values. The property values are stored in objects of special property classes which are automatically generated from the property set definitions. Performance-critical code can be inlined by the compiler and a typical access to a property value is as cheap as reading a single variable from the memory. No costly data structures like hashes or balanced trees etc. are involved.