This article discusses some developments relating to environments for Csound programming, composition and performance. It introduces the Csound 5 API and discusses its use in the development of a TclTk scripting interface, TclCsound. The three components of TclCsound are presented and discussed. A number of applications, from simple transport control of Csound to client-server networking are explained in some detail. The new multi-platform version of CECILIA is presented. Cecilia is the first Csound frontend to use the functionalities of TclCsound.