Communication service provider ambitions to profitably leverage their network capabilities, provide novel differentiating services, and potentially even to tap into the talents of global development communities motivates the idea of a flexible service platform and service creation environment. Optimally, the platform should include a multiplicity of enablers that provide convenient programming interfaces to network elements and an environment where those enablers may be woven into composite services. The Service Composition Framework (SCF) for Alcatel-Lucent's Open API Platform is robust and sophisticated middleware for hosting composite services. Such services can be created by third parties via an innovative service creation environment. The SCF is built on a core of open source software, with the valuable addition of a maintenance infrastructure, and a suite of services, enablers, policies, and utilities to support new services. This paper also describes the SCF's run-time hosting of composite services, their configuration, and their creation using the companion SCE. © 2013 Alcatel-Lucent.