As people have come to realize that the use of technology can improve the learning process, so e-learning has increased in importance. However e-learning tools are not usually developed to interoperate with each other, making the creation of a fully functional environment a difficult task. Aware of this problem, organizations such as IMS Global Learning Consortium, Advanced Distributed Learning and IEEE Learning Technology Standards Committee are working to develop technical standards, recommended best practices and guides for learning technology. There are also proposals for e-learning architectures which try to structure and describe the fundamental components to be included in this kind of environment. The main aim of this chapter is to provide an overview of existing standards and e-learning architectures, discussing their evolution and presenting the most significant results and initiatives. In addition, accessibility, digital libraries and semantic web technologies are discussed within this context.