This paper presents a template-based solution to overcome technical barriers non-technical computer end users face when developing functional learning environments in three-dimensional virtual worlds (3DVW). "iVirtualWorld," a prototype of a platform-independent 3DVW creation tool that implements the proposed solution, facilitates 3DVW learning environment creation through semantics-based abstract 3DVW representation and template-based 3DVW instantiation. "iVirtualWorld" provides a wizard to guide the 3DVW creation process, and hide low-level programming and 3D design details through higher-level abstracts supported by pre-defined templates. Preliminary evaluation of the effectiveness of "iVirtualWorld" showed positive results. The contribution of this study is threefold: (1) It provides a paradigm for investigating and developing 3DVW building tools from end users' perspective; (2) It develops a prototype of a 3DVW building tool, which gives educators a framework to easily create educational virtual worlds using domain-specific concepts; and (3) It conducts empirical research and collected preliminary experimental data for evaluation.