Computational media describes a vision of software, which, in contrast to application-centric software, is (1) malleable, so users can modify existing functionality, (2) computable, so users can run custom code, (3) distributable, so users can open documents across different devices, and (4) shareable, so users can easily share and collaborate on documents. Over the last ten years, the Webstrates and Codestrates projects aimed to realize this vision of computational media. Webstrates is a server application that synchronizes the DOM of websites. Codestrates builds on top of Webstrates and adds an authoring environment, which blurs the use and development of applications. Grounded in a chronology of the development of Webstrates and Codestrates, we present eight tensions that we needed to balance during their development. We use these tensions as an analytical lens in three case studies and a game challenge in which participants created games using Codestrates. We discuss the results of the game challenge based on these tensions and present key takeaways for six of them. Finally, we present six lessons learned from our endeavor to realize the vision of computational media, demonstrating the balancing act of weighing the vision against the pragmatics of implementing a working system. CCS Concepts: • Human-centered computing → Interactive systems and tools; Empirical studies in HCI ; Web-based interaction; Collaborative interaction.