# Compatibility with OLE 1

Compatibility between OLE 2 and OLE 1 applications is achieved through the implementation of two types of special remoting objects, called stubs and proxies. The stub is instantiated on the object, or server, application’s side of the process; the proxy is instantiated on the container, or client, application’s side. These special stubs and proxies use DDE to communicate rather than LRPC. When an OLE 2 object makes a call to a function in an OLE 1 client application, for example, the stub intercepts the call and responds appropriately. For the most part, this response simulates the response that an OLE 2 object or container would make. However, in a few cases the behavior is different or special HRESULT (SCODE) values are returned.

This chapter discusses the issues that affect applications that must be compatible with an earlier or more recent version of OLE and describes the functions that promote this compatibility.