The knowledge grid environment is an autonomous human-machine environment evolving with science, technology, culture, and society. It consists of autonomous individuals, self-organized semantic communities, an adaptive-networking mechanism, and an evolving semantic networking mechanism. A memex extension (ME) offers a general model for autonomous individuals in this environment. MEs are configurable, adaptive, and context-aware digital organisms that model various types of network resources and host distributed network software and devices. MEs organize themselves to perform tasks according to social and economical principles. The evolving environment supports the generation of new MEs through inheritance. The ME model is also a knowledge model that can actively detect problems and fuse with and inherit from others' knowledge to obtain a reputation in providing knowledge services. The ME models advance information and knowledge in the knowledge grid environment.