Google Closure Templates is a lightweight, language‑neutral templating system (for Java and JavaScript) that lets developers compose reusable HTML/UI fragments by writing simple, function‑style templates that can be pre‑compiled to efficient JavaScript on the client side. It’s aimed at programmers who need a fast, secure way to separate presentation from logic—especially those building large‑scale web apps (e.g., Gmail, Docs) or sharing templates between server and client code.