BrowserCraft allows you to play a near-complete version of Minecraft Classic (specifically version 0.0.23a_01) directly in your web browser, thanks to the CheerpJ Java to JavaScript/WebAssembly compiler. It requires no installation or plugins, boasting full multiplayer support and even the ability to connect to existing Java Minecraft Classic servers. While aiming for feature parity with the original client, some differences exist, notably enhanced performance in certain areas and potential discrepancies in rendering. The project is open-source and actively being developed, welcoming community contributions.
This blog post details a remarkable feat of software engineering: running a modified version of Minecraft, the popular voxel-based sandbox game, entirely within a web browser, without requiring any client-side installations or plugins. The project, dubbed "Browsercraft," leverages the CheerpJ Java to JavaScript/WebAssembly compiler to achieve this. Originally, Minecraft was written in Java, a language not natively supported by web browsers. CheerpJ overcomes this limitation by converting the Java bytecode of the Minecraft client into a format executable by browsers, specifically JavaScript and, for enhanced performance, WebAssembly.
The post explains that Browsercraft is not simply a proof of concept but a functional, albeit modified, version of Minecraft Classic. Players can join multiplayer servers and experience core gameplay elements, including block breaking, placement, and basic crafting. It emphasizes that the entire game logic, originally implemented in Java, is now executing within the browser environment thanks to the CheerpJ conversion process.
The author delves into some of the technical challenges encountered and solutions implemented during the project. A key challenge was handling Minecraft's reliance on native libraries, code specifically designed for the operating system Minecraft typically runs on. The solution involved utilizing a custom implementation of the LWJGL (Lightweight Java Game Library) rewritten specifically to be compatible with CheerpJ and the browser environment. This custom LWJGL implementation provides the necessary abstractions for graphics rendering, audio output, and input handling within the browser context.
Furthermore, the post highlights the performance improvements observed when leveraging WebAssembly as the compilation target for CheerpJ. WebAssembly, a binary instruction format designed for web browsers, offers significant performance gains compared to JavaScript, resulting in a smoother and more responsive gameplay experience within Browsercraft.
Finally, the author concludes by showcasing the potential of CheerpJ and WebAssembly to enable the execution of complex Java applications, like Minecraft Classic, entirely within web browsers, opening up new possibilities for accessibility and distribution of Java-based software. The post provides a link to a live demonstration of Browsercraft, allowing readers to experience the project firsthand.
Summary of Comments ( 9 )
https://news.ycombinator.com/item?id=43535769
HN commenters express excitement and curiosity about the technical implementation of a Java Minecraft clone running in the browser. Several discuss the clever use of CheerpJ, a Java-to-WebAssembly compiler, noting its surprisingly good performance and suitability for CPU-bound tasks like Minecraft's game logic. Some commenters raise concerns about performance bottlenecks, particularly related to rendering and garbage collection, while others offer potential optimizations. The project's open-source nature and availability on GitHub are praised, with some expressing interest in contributing. A few commenters reminisce about similar projects in the past, comparing their performance and approaches. The overall sentiment is positive, with the project viewed as an impressive technical feat and a promising demonstration of WebAssembly's capabilities.
The Hacker News post titled "Java Minecraft in the Browser" (linking to https://browsercraft.cheerpj.com/) generated a moderate amount of discussion, with several commenters expressing interest and sharing their perspectives.
A recurring theme is the impressive technical feat of running Minecraft, a Java application, within a web browser. Several comments highlight the use of CheerpJ, a Java to WebAssembly/JavaScript compiler, as the key enabling technology. Commenters marvel at how far web technology has come, allowing for such complex applications to run smoothly within the browser environment. Some express surprise and even disbelief, prompting further explanations from others familiar with CheerpJ and similar technologies.
Some commenters discuss the performance of Browsercraft, with general agreement that it runs surprisingly well given the circumstances. While acknowledging it's not perfect, the consensus seems to be that the performance is impressive for a Java application running within a browser. One commenter even reports a positive experience playing on a low-powered Chromebook.
A few comments delve into the technical details of CheerpJ and how it achieves this. One user mentions the ability of CheerpJ to provide access to the underlying operating system through a virtualized DOM, which allows the Java application to interact with browser APIs. Another commenter clarifies that while CheerpJ doesn't interpret Java bytecode directly, it effectively re-implements the Java runtime environment using WebAssembly, enabling execution within the browser.
The discussion also touches on the potential implications of this technology. Some commenters speculate about the possibility of running other Java applications, or even entire operating systems, within the browser. Others discuss the benefits of using Java for game development, such as portability, while acknowledging its performance limitations compared to native code.
Several commenters express concerns related to security and the potential for abuse of this technology. They raise the possibility of malicious actors using this to distribute malware disguised as seemingly harmless Java applications running within the browser.
Finally, some comments simply share amusement or express general enthusiasm for the project, often expressing nostalgia for Minecraft. One commenter jokingly requests a version of RuneScape running in the browser.
Overall, the comments reflect a positive reception to the project, with many expressing amazement at the technical achievement and speculating on the potential future applications of such technology, while also acknowledging potential downsides like security risks.