Dependability and extensibility are two of the key requirements to successful home networking. In this paper, we describe the design and implementation of a software development toolkit for building dependable and extensible home networking applications. A Soft-State Store (SSS) is implemented as a shared infrastructure to simplify robust distributed programming against device and object failures. SSS supports multi-timescale refreshes and selectively uses persistence to accommodate the battery power and network bandwidth constraints in the home networking environment. A publish/subscribe event system allows any changes in the SSS to be propagated to interested subscribers, which then perform appropriate adaptive, corrective, alerting, or cleanup actions. An Attributed-Based Lookup Service (ABLS) and a Name-Based Lookup Service (NBLS), both implemented on top of the SSS for robustness, provide one level of indirection for supporting extensibility as well as allow user-friendly, natural language-based access. We demonstrate the use of the toolkit for building home networking applications in an actual deployment and present performance numbers.