Altlauncher

A free, open-source Minecraft launcher (beta version)

What is it?

Altlauncher was created back in 2024 as a modern and more stable launcher for the Altbeta project.

Now, in 2026, it is experiencing a revival, with new features and a more classic layout similar to many classic launchers.

How to use

This software was developed for use within the altBeta4 ecosystem. To set it up correctly, you’ll need an S3-like interface to provide the necessary libraries, as well as an authentication backend. You can find more details in the project wiki, which explains what you need to change and where to get started.

To connect Altlauncher to your backend, simply change three lines in different files:

1. Altlauncher.java:97 - "Need account?" link.
2. Altlauncher.java:110 - URL for the news screen (Note: the built-in browser only supports very old HTML!)
3. Authenticator.java:7 - HTTPS link to the authentication backend. If you’re using ours, simply enter the path to the getsession.php file. Otherwise, check out our Wiki.
4. Downloader.java:12 - HTTPS link to the S3 storage containing the libraries. See the Wiki for instructions on how to configure it.

How to build

The project was entirely configured and developed using the Eclipse IDE, which handles the build process automatically. The easiest way to build it yourself is to use Eclipse:

1. Download and install Eclipse IDE for Java Developers.
2. Install Liberica JDK 8 (LTS). It was used for development and is highly recommended for compatibility. You can download it here: BellSoft Liberica JDK 8. Be sure to check that it is specified in the Eclipse settings as the installed JRE.
3. Clone this repository or import it into your Eclipse workspace (File -> Import... -> Git -> Projects from Git).
4. Eclipse will automatically compile the project upon import.
5. To export the final executable file, right-click on the project root -> Export... -> Java -> Runnable JAR file.
6. Follow the wizard setup to select your launch configuration and save the .jar file.

License

Since 2.0, Altlaunchr is distributed under the GPLv3 license, the text of which can be found in the LICENSE.md file.

TL;DR

1. Anyone can copy, modify, and distribute this software.
2. You must include the license and copyright notice with every distribution.
3. You can use this software for personal use.
4. You can use this software for commercial purposes.
5. If you dare to build your business solely on this code, you risk having to open-source the entire codebase.
6. If you modify it, you must indicate the changes made to the code.
7. Any modifications to this codebase MUST be distributed under the same license, GPLv3.
8. This software is provided without warranty.
9. The software author or licensor cannot be held liable for any damages caused by the software.