Developers of online professional development with an emphasis on science, technology, engineering, and mathematics education write about what they have learned in the process of designing and implementing their professional development models. The material is to help researchers and other developers understand the range of effective models and their conditions for success. Covering course, curriculum support, and resources and strategies, they discuss such topics as professional learning with web-based videos: the talk science experiment, supporting deep change with an immersive online course, online teacher professional development from the American Museum of Natural History, the project-based inquiry science cyberlearning professional development system, and making online and blended teacher professional development accessible. Annotation ©2016 Ringgold, Inc., Portland, OR (protoview.com)