although each new release of delphi attempts to keep as much backwards compatibility as possible to allow existing code reuse, new features, new libraries, and improvements sometimes make newer releases less than 100% backwards compatible. for example, the design of the standard class libraries (vcl/rtl) had become somewhat dated and restrictive; embarcadero released in 2011 as part of delphi xe2 a new compiler and cross-platform vcl replacement called firemonkey, based on direct3d and opengl, which runs on other platforms in addition to windows, supporting their features, but is not fully backwards-compatible with vcl applications. firemonkey applications do however allow easy sharing of non visual code units with vcl applications, enabling a lot of code to be ported easily between the platforms.