The proposed Taxonomy of Virtual Worlds for Education workshop will bring together a group of practitioners (especially teachers and students), researchers, and technology providers to brainstorm the ideal virtual world software system(s) for STEM learning. The goal is to ensure that the evolution of the medium is informed from the beginning by the user community. From experience, educators have found that each system has both attractive and detracting features when considered for use in educational settings. This workshop is intended specifically to flesh out the landscape of educational virtual world applications: What would the ideal system for educational applications look like? In particular, what are the best ways to manage tasks specific to education? This workshop will center on (but not be restricted to) primarily K-12 education both from the points of view of teachers and students in classroom and informal settings and from the perspective of teacher professional development and support professionals. This workshop will build a taxonomy of features/affordances/capabilities derived from across the spectrum of systems available and then create a matrix (multidimensional and/or suite of matrices) that can be used by STEM educators as they search for appropriate software solutions.