Ambient Learning Spaces (ALS) is a platform to create, use, and manage digital teaching and learning environments. The concepts for ALS have been based on contemporary pedagogical theories in awareness that learning processes are going to be less dependent on teaching technologies and content and more on the active processes of learning itself. ALS has been developed over more than 15 years in a series of research projects. ALS enables individuals as well as groups of learners to create, share, distribute, and reuse semantically annotated media in social teaching and learning processes. The central component of ALS, the Network Environment for Multimedia Objects (NEMO), forms the media and logic backend for multimodal interactive frontend learning applications. It is a cloud-based repository and allows the creation of semantically annotated multimedia content to be used across all ALS learning applications. These ALS applications can be used on mobile, stationary, and immersive interactive systems such as domes, large screens, tangibles, mobiles, and wearables. Media content in form of text, image, video, or 3D can be reused and shared by different learning applications and will be adapted on the fly as needed for various interaction devices with different interaction modalities. Interaction methods depending on the available devices reach from direct manipulation interfaces on touch displays to mobile augmented reality and interactive 360° virtual reality applications. Plain media can be constructed into Knowledge Media by semantic mark¬ups. Through the ALS Portal, teachers and learners include, edit, annotate, and semantically model their own media. Special user interfaces like tangible media and large multi-touch screens as well as mobile media and wearables enable body- and space-related post-constructivist learning in real life contexts. ALS has been used in schools, museums, universities, biotopes, and urban spaces in pilot installations with different configurations, some of them being used in long-term studies over years.