There is a growing need for Vehicle Networking Applications (VNAs) development that does not require users to learn the details of VNA data processing and message transfer. VNAs have some special requirements differing from other general-purpose applications, such as real-time performance, extensibility, compatibility, and reusability. To meet with these requirements of the VNAs, we propose a lightweight middleware framework for VNAs in this article. In the middle framework, we design multi-layer middleware architecture to separate VNAs from the software platform and to improve the adaptability for the heterogeneous network and various vehicle networking communication protocols. Meanwhile, the middleware architecture consists of fixed and exchangeable modules to improve the middleware reusability. And the component bus is presented in a framework to standardize component interfaces to improve the extensibility of middleware. The framework has an efficient and simple structure to guarantee the real-time performance of data processing and message transferring. This middleware also provides a uniform communication mechanism to be compatible with other existing middleware. In this article, we describe the design ideas and the composition of each module in the middleware framework, and analyze the data flow in communication process. We also develop the middleware prototypes to verify the feasibility of the middleware framework.development. How to develop and integrate the difference middleware together to serve VITs is the key issue for VNAs developers.Meanwhile, there are multiple kinds of communication networks in VNAs, including in-vehicle network, inter-vehicle network, vehicular body network, and the Internet. They take different network technologies, such as WiFi (Wireless Fidelity) and Bluetooth for in-vehicle network, DSRC (Dedicated Short-Range Communications) [1] for inter-vehicle network, 3G (the 3rd Generation mobile communication network) and WiFi for Internet, and CAN (Controller Area Network) or FlexRay for vehicular body network. Multiple types of networks are integrated together to serve one VNA. So, the reusability and the portability of VNAs become worse. How to hide different network communication interfaces and how to switch networks according to requirements are the problems for VNA communication.To facilitate the development of VNAs on the existing software platforms, how to deal with the occurring problems in VNA development and how to improve the development efficiency of VNAs become more and more urgent. These problems are the obstacles to develop a universal VNA. Up to now, there are still no uniform application standards for vehicular network. Middleware is used widely as a desirable method for most developers to reduce redevelopment and to hide the heterogeneity of lower-layer software and hardware. So, it is necessary to provide one middleware framework for VNAs, which has a simple, adaptive, and extensible structure to hide the heterogeneity of a network and platform, and improve the gen...