NeoLauncher is a modern Minecraft launcher focused on easy instance management, modding, diagnostics, performance, and troubleshooting.
NeoLauncher is a fork of Prism Launcher and is not endorsed by or affiliated with the Prism Launcher project.
Prism Launcher itself is a fork of MultiMC.
NeoLauncher builds on top of Prism Launcher's powerful instance management while introducing additional tools focused on usability, diagnostics, recovery, and performance.
Some of the features planned or provided by NeoLauncher include:
- Multiple isolated Minecraft instances
- Modrinth and CurseForge integration
- Fabric, Forge, NeoForge, Quilt, and other supported mod loaders
- Automatic Java management
- Optional Microsoft account support for online services, with local/offline use available without mandatory sign-in
- Mod, resource pack, shader, and datapack management
- Neo Doctor
- Crash Analyzer
- Neo Optimizer
- Instance Health
- Instance snapshots and rollback
- Mod Profiles
- Instance testing
- Neo Sync
- Server Profiles
- Extension support
NeoLauncher aims to make heavily modded Minecraft installations easier to manage without taking advanced controls away from experienced users.
- Available: Debian-family validation, independent Neo branding, offline English/Portuguese selection, consent-based, backed-up Prism-data reuse, Neo Doctor, local Crash Analyzer, Instance Health, conservative Neo Optimizer recommendations, transactional snapshots, Mod Profiles, reviewed-plan local-folder Neo Sync, Server Profiles, disposable Test Instance launch, the optional dockable Neo Dashboard with recent instances/quick actions/persistent local notifications, extension manifest validation/manager, Bubblewrap-isolated external execution with versioned JSON IPC, and
--safe-mode.
External extensions run only after explicit permission consent and a separate Run action. NeoLauncher fails closed when Bubblewrap is unavailable, never loads third-party native Qt libraries, mounts only the extension package and system runtime read-only (no launcher or user-data paths), and grants networking only when network.access was declared and accepted.
Feature guides: English · Português do Brasil
Internal implementation and validation report: docs/internal/implementation-report.md
NeoLauncher currently targets full support for:
- English
- Português do Brasil
The language selected during the initial setup is used throughout the launcher.
The language can also be changed later through the launcher settings.
All NeoLauncher-specific features should provide both English and Brazilian Portuguese translations.
Stable releases of NeoLauncher will be published on the project's GitHub Releases page after the release validation gates pass:
Build status can be found in:
Supported operating systems:
- Debian-based Linux distributions only.
NeoLauncher is compatible only with Debian-based Linux distributions. Windows, macOS, Arch Linux, Fedora, RHEL, openSUSE, and other non-Debian-derived systems are not supported.
See System Requirements or Requisitos do sistema.
Development builds contain the newest NeoLauncher changes and features.
They are intended primarily for testing and development.
Please understand that development builds may contain:
- bugs;
- unfinished functionality;
- regressions;
- debug information;
- compatibility issues.
Development builds can be obtained through:
Development binaries may be considerably larger than release binaries because they can contain debugging information.
Do not use development builds for important Minecraft instances without keeping backups or snapshots.
Neo Doctor is NeoLauncher's integrated instance diagnostics system.
It can inspect an instance for common configuration and compatibility problems involving areas such as:
- Java versions
- memory configuration
- mod loaders
- missing dependencies
- mod conflicts
- corrupted or missing files
- instance configuration
- runtime problems
When a safe automatic solution is available, NeoLauncher may provide an option to fix the issue directly.
Potentially destructive fixes should create a snapshot before changing the instance.
NeoLauncher includes an integrated crash analysis system designed to make Minecraft crashes easier to understand.
The Crash Analyzer can inspect:
- Minecraft logs
- crash reports
- JVM errors
- mod loader errors
- exceptions
- exit codes
It can recognize common problems such as:
NoClassDefFoundErrorClassNotFoundException- missing mod dependencies
- incompatible mods
- duplicate mods
- incompatible Java versions
OutOfMemoryError- loader failures
- JVM startup failures
Crash analysis is designed to work locally.
NeoLauncher should not automatically upload crash reports, logs, credentials, account information, or other private information to third-party services.
Neo Optimizer provides recommendations based on the Minecraft instance and the user's hardware.
It may analyze information such as:
- CPU
- GPU
- system memory
- operating system
- Java version
- Minecraft version
- mod loader
- installed mods
Optimization presets may include:
- Vanilla
- Balanced
- Performance
- Low Memory
- Modded
- Custom
Neo Optimizer should recommend changes instead of silently modifying an instance.
NeoLauncher can create snapshots before significant instance changes.
Snapshots can be created before operations such as:
- Minecraft upgrades
- loader upgrades
- modpack upgrades
- bulk mod updates
- Neo Doctor fixes
- Crash Analyzer fixes
- Neo Optimizer changes
- Server Profile updates
Snapshots allow the instance to be restored if an update or configuration change causes problems.
Whenever possible, NeoLauncher should use efficient incremental storage instead of copying an entire Minecraft instance for every snapshot.
NeoLauncher can provide a health status for Minecraft instances based on diagnostic information.
Instance Health can consider:
- Java compatibility
- loader status
- dependencies
- mod conflicts
- instance integrity
- memory configuration
- recent crashes
Possible states include:
- Healthy
- Attention Needed
- Problems Detected
- Critical
Available updates alone should not cause an instance to be considered unhealthy.
NeoLauncher supports the concept of multiple mod configurations inside a single Minecraft instance.
For example:
My Fabric Instance
Profiles:
- Default
- Performance
- Shaders
- Multiplayer
- Testing
Profiles can enable or disable different sets of mods without requiring the user to maintain several duplicate Minecraft instances.
NeoLauncher can provide tools for testing an instance before normal gameplay.
An instance test may verify whether:
- Java starts correctly;
- Minecraft starts;
- the selected mod loader initializes;
- installed mods are discovered;
- critical errors occur during startup.
The test system may also report information such as startup time, peak memory usage, warnings, and process exit status.
Neo Sync is designed to provide an extensible synchronization system for Minecraft instances and launcher data.
Possible synchronization providers include:
- Local Folder
- WebDAV
- Nextcloud
- Google Drive
- other providers through future integrations
Sensitive information such as Microsoft authentication tokens, passwords, API keys, and credentials should never be included in normal synchronization data.
NeoLauncher Server Profiles allow Minecraft servers and communities to distribute a versioned configuration describing the Minecraft environment required by the server.
A profile may specify:
- Minecraft version
- mod loader
- mods
- dependencies
- server address
- file hashes
Before applying a Server Profile update, NeoLauncher should display the changes and create an instance snapshot.
Remote profiles must not be allowed to execute arbitrary commands or write files outside the target Minecraft instance.
NeoLauncher is designed to support an extensible architecture.
Future extensions may integrate additional functionality without requiring every feature to become part of the launcher core.
Extension support should include:
- API versioning
- compatibility checks
- controlled lifecycle
- error isolation
- extension logging
- enable/disable controls
- Safe Mode
A broken third-party extension should not prevent NeoLauncher itself from starting.
NeoLauncher is designed with local-first diagnostics and instance management in mind.
NeoLauncher should never silently upload:
- Minecraft logs
- crash reports
- Microsoft account information
- authentication tokens
- passwords
- API keys
- server information
- local file paths containing personal information
Features that require sending information to an external service must clearly explain what will be transmitted and require user consent where appropriate.
If you find a bug or want to suggest a feature, open an issue:
For development-related discussions, you can also use:
Additional community channels may be added in the future.
Contributions to NeoLauncher are welcome.
Before submitting a pull request:
- Make sure the project builds successfully.
- Run the relevant tests.
- Follow the existing code style.
- Avoid introducing unnecessary dependencies.
- Keep new user-facing strings translatable.
- Add both English and Brazilian Portuguese translations for NeoLauncher-specific functionality whenever applicable.
- Add tests for new non-trivial functionality.
Pull requests can be submitted at:
NeoLauncher-specific features are expected to support at least:
- English
- Brazilian Portuguese (
pt-BR/pt_BR, according to the translation system used by the project)
User-facing strings should use the launcher's translation system and must not be unnecessarily hardcoded into application logic.
Additional translations inherited from Prism Launcher should remain available whenever possible.
Contributions for additional languages are welcome.
NeoLauncher is built and packaged only on Debian-based Linux distributions. Install the documented APT dependencies, then use the repository presets:
cmake --preset linux
cmake --build --preset linux --config Debug
ctest --preset linux --build-config Debug
cpack --config build/CPackConfig.cmake -C Release -G DEB -B packagesThe complete dependency list, release build, and .deb validation commands are documented in docs/en/building.md and docs/pt_BR/compilacao.md.
NeoLauncher would not exist without the work of the projects it is based on.
NeoLauncher is a fork of:
Prism Launcher is an open-source Minecraft launcher providing powerful management for multiple isolated Minecraft installations.
NeoLauncher is an independent project and is not endorsed by, sponsored by, or affiliated with the Prism Launcher project.
Prism Launcher itself originates from the MultiMC ecosystem.
The NeoLauncher project recognizes and appreciates the work of the MultiMC developers and all contributors whose work eventually became part of the upstream codebase.
Parts of the upstream Prism Launcher codebase integrate with third-party services and APIs such as:
- Microsoft
- CurseForge
- Modrinth
NeoLauncher maintainers are responsible for configuring their own API credentials where required.
Credentials belonging to Prism Launcher must not be reused by NeoLauncher unless explicitly authorized.
NeoLauncher is open-source software and may be forked, modified, and redistributed according to the terms of its license.
If you redistribute a modified version of NeoLauncher, please make it clear that your version is not the official NeoLauncher project and is not endorsed by or affiliated with NeoLauncher.
You are responsible for replacing API credentials, application identifiers, update endpoints, branding, and other infrastructure-specific configuration with your own where required.
If you are packaging an unmodified NeoLauncher build for a Linux distribution, use the appropriate build platform identifier where supported by the build system.
NeoLauncher is derived from Prism Launcher.
API credentials included in upstream source code must be reviewed before distributing NeoLauncher builds.
Where necessary, replace upstream credentials with NeoLauncher-specific credentials or disable the related functionality by using empty values where supported.
Depending on the enabled integrations, applicable terms may include:
Maintainers are responsible for ensuring that their distributed builds comply with the applicable service terms.
NeoLauncher is derived from Prism Launcher and the launcher source code remains available under the GPL-3.0-only license.
See LICENSE for the complete license text.
Some NeoLauncher artwork may be derived from or inspired by Prism Launcher assets.
Prism Launcher states that its logo and related assets are licensed under CC BY-SA 4.0.
Any derivative artwork must preserve the attribution and licensing requirements applicable to the original work.
See the repository's artwork/license documentation for details.
NeoLauncher is an independent open-source project.
It is:
- not an official Minecraft product;
- not approved by or associated with Mojang Studios;
- not approved by or associated with Microsoft;
- not endorsed by or affiliated with Prism Launcher;
- not endorsed by or affiliated with MultiMC.
Minecraft is a trademark of Microsoft Corporation.