The purpose of this paper is to examine how an actor strategically develops and diffuses technology standards that align with innovation trajectories while maintaining a consensus with competitors. We conduct a field study of HTML5 standardization and examine how Google strategically influences the development and diffusion of HTML5 toward their favorable standard trajectories. We show that Google has adopted two strategic policies (integrating outside technologies and avoiding the monetization of technologies) and engaged in two relational practices (forming alliances with browser vendors and engaging developer communities) to realize an open Web application platform on the HTML5 while competing and coordinating with other actors. Google attracts application developers and browser vendors to collaboratively develop HTML5 specifications and HTML5-compatible products and services, which have enriched Google's open Web application strategy. These relational practices were enabled and amplified by non-commercial policies for corresponding web applications and the use of other parties' technologies.