Freedom251 › Minecraft Launchers
SJMCL
What SJMCL is
SJMCL, also called SJMC Launcher, is a free, open-source Minecraft launcher for Windows, macOS, and Linux. Built with the Tauri framework, it keeps multiple game directories and instances separate, including their saves, mods, resource packs, shaders, screenshots, and settings. It downloads game clients, mod loaders, resources, and modpacks from sources such as CurseForge and Modrinth, with modpack import supported in both directions. Multiple mod loaders are supported, Java runtimes can be managed, and automatic updates are available. Microsoft sign-in, third-party authentication servers, and the proposed Yggdrasil Connect OAuth flow are supported. Deep links connect external webpages and programs, while an MCP service can connect agent applications and automate the running launcher. Windows installers and portable builds, macOS Apple Silicon and Intel files, and Linux packages are listed. Some features may vary by region, platform, or distribution type. The maker says SJMCL is not an official Minecraft product or affiliated with Mojang or Microsoft.
Who it suits
SJMCL suits Minecraft players who want separate instances, modpack and mod-loader support, and Java management across Windows, macOS, or Linux. It may also suit users needing external integrations or launcher automation.
What it does well
- Free plan available
- Supports Windows, macOS, and Linux
- Manages multiple instances and game directories
- Supports multiple mod loaders
- Automatic updates available
What to know first
- Some features vary by region or platform
- Extensions are marked coming soon
- Not affiliated with Mojang or Microsoft
Verdict
SJMCL combines instance organization, mod downloads, account options, and external integrations in a free cross-platform launcher. Check platform-specific feature availability and the non-affiliation disclaimer before using it.
Facts from SJMCL's own pages
- Accounts
- It supports Microsoft sign-in and third-party authentication servers, and is compatible with the Yggdrasil Connect OAuth login flow proposal. · mc.sjtu.cn, 11 Oct 2026
- Audience and affiliation
- The launcher was initiated by members of Shanghai Jiao Tong University Minecraft Club and is developed with open-source community contributors. · mc.sjtu.cn, 11 Oct 2026
- Automatic updates
- Yes · mc.sjtu.cn, 23 Sept 2026
- Automation
- Its MCP service lets external Agent applications automate the launcher while it is running. · mc.sjtu.cn, 11 Oct 2026
- Disclaimer
- The maker states that SJMC Launcher is not an official Minecraft product and is not approved by or affiliated with Mojang or Microsoft. · mc.sjtu.cn, 11 Oct 2026
- Download formats
- Downloads include Windows x86, x64, and ARM64 installers and portable versions; macOS Apple Silicon and Intel DMG and App Bundle files; and Linux DEB, RPM, and portable versions. · mc.sjtu.cn, 11 Oct 2026
- Downloads
- It supports downloading game clients, mod loaders, game resources, and modpacks from sources including CurseForge and Modrinth. · mc.sjtu.cn, 11 Oct 2026
- Extensions
- The launcher supports developing extensions, though the documentation marks this feature as coming soon. · mc.sjtu.cn, 11 Oct 2026
- External integrations
- Deep links and an MCP service let it work with external webpages, programs, and agent services. · mc.sjtu.cn, 11 Oct 2026
- Feature availability
- The maker says some features may be limited by region, operating platform, or distribution type. · mc.sjtu.cn, 11 Oct 2026
- Feature limits
- The maker says some features may be limited by region, operating platform, or distribution type. · mc.sjtu.cn, 11 Oct 2026
- Free plan
- Yes · mc.sjtu.cn, 23 Sept 2026
- Instance management
- It manages multiple game directories and instances, including saves, mods, resource packs, shaders, screenshots, and settings. · mc.sjtu.cn, 11 Oct 2026
- Instances
- It manages multiple game directories and instances, including saves, mods, resource packs, shader packs, screenshots, and settings. · mc.sjtu.cn, 11 Oct 2026
- Java runtime management
- Yes · mc.sjtu.cn, 23 Sept 2026
- MCP integration
- The documentation gives setup instructions for connecting the launcher to Cherry Studio over HTTP. · mc.sjtu.cn, 11 Oct 2026
- Mod loader support
- multiple · mc.sjtu.cn, 23 Sept 2026
- Modpack import
- both · mc.sjtu.cn, 23 Sept 2026
- Operating systems
- The maker lists compatibility with Windows 10/11, macOS, and Linux. · mc.sjtu.cn, 11 Oct 2026
- Platforms
- The download page lists Windows x86, x64, and ARM64; macOS Apple Silicon and Intel; and Linux packages. · mc.sjtu.cn, 11 Oct 2026
- Privacy
- The user agreement says the software may send its version and operating system version to the maker’s servers and does not collect personal information. · mc.sjtu.cn, 11 Oct 2026
- Product
- SJMC Launcher is an open-source, cross-platform Minecraft launcher built with the Tauri framework. · mc.sjtu.cn, 11 Oct 2026
- Product status
- The maker says the software is not an official Minecraft product and is not approved by or affiliated with Mojang or Microsoft. · mc.sjtu.cn, 11 Oct 2026
- Project
- The project was initiated by members of the Shanghai Jiao Tong University Minecraft Society and is developed and maintained with open-source community contributors. · mc.sjtu.cn, 11 Oct 2026
Where SJMCL stands on Freedom251
- Minecraft Launchers#31 of 76