Atmosphère is a work-in-progress customized firmware for the Nintendo Switch.

Atmosphère consists of multiple components, each of which replaces/modifies a different component of the system:

• Fusée: First-stage Loader, responsible for loading and validating stage 2 (custom TrustZone) plus package2 (Kernel/FIRM sysmodules), and patching them as needed. This replaces all functionality normally in Package1loader/NX Bootloader.
• Exosphère: Customized TrustZone, to run a customized Secure Monitor
• Thermosphère: EL2 EmuNAND support, i.e. backing up and using virtualized/redirected NAND images
• Stratosphère: Custom Sysmodule(s), both Rosalina style to extend the kernel/provide new features, and of the loader reimplementation style to hook important system actions
• Troposphère: Application-level Horizon OS patches, used to implement desirable CFW features

Atmosphère is currently being developed and maintained by SciresM, TuxSH and hexkyz.
In no particular order, we credit the following for their invaluable contributions:

• switchbrew for the libnx project and the extensive documentation, research and tool development pertaining to the Nintendo Switch.
• devkitPro for the devkitA64 toolchain and libnx support.
• ReSwitched Team for additional documentation, research and tool development pertaining to the Nintendo Switch.
• ChaN for the FatFs module.
• Riley for suggesting "Atmosphere" as a Horizon OS reimplementation+customization project name.
• naehrwert for the hekate project and its hwinit code base.
• hedgeberg for research and hardware testing.
• lioncash for code cleanup and general improvements.
• jaames for designing and providing Atmosphère's graphical resources.
• Everyone who submitted entries for Atmosphère's splash design contest.
• All those who actively contribute to the Atmosphère repository.