Every form of lapstack, free.
The browser app needs nothing installed. The desktop application, the command-line tool and the Lightroom plugin are built for each release and published on GitHub, for Linux, Windows and macOS; the source builds in a few minutes with cargo. They are the same engine, the same files and the same manual.
Desktop application
The browser app packaged with Electron, which bundles a Chromium that has WebGPU on every platform. No launcher flags and no browser configuration; native folder pickers and Save As dialogs. It is the answer for anyone whose browser makes WebGPU a nuisance — which on Linux, at the moment, is most of them.
Linux
x86-64 · AppImage and Debian package
Latest release →- Needs a Vulkan-capable GPU driver
- The AppImage runs from anywhere once it is made executable; the
.debinstalls on Debian and Ubuntu
Windows
x86-64 · installer
Latest release →- Windows 10 and 11, any Direct3D 12 GPU
- Not code signed: SmartScreen warns on first launch — More info › Run anyway
macOS
Apple silicon and Intel · disk images
Latest release →- macOS 13 and later, Metal, so any supported Mac
- Not notarized: open it the first time with right-click › Open, or clear the
quarantine flag with
xattr -d com.apple.quarantine
The builds are made on GitHub's machines by the release workflow in the repository. The Linux build has had the most use; if a Windows or macOS build misbehaves on your machine, say so at support@ragtux.com or in an issue. Every page of the manual applies to the desktop build unchanged. About the desktop application →
Command-line tool
lapstack is a single native binary. It has no stack-size ceiling, streams frames
from disk so memory stays flat however long the stack, and runs on the GPU with
--gpu: CUDA where the machine has it, and otherwise the browser app's own kernels
through Vulkan, Metal or Direct3D 12. Each release carries an archive per platform —
Linux x86-64, Windows x86-64, macOS on Apple silicon and on Intel.
Two files that belong together
The lapstack binary, and beside it the camera raw decoder — a module of
its own that the program loads when it meets a raw file. Keep the two together, or point
LAPSTACK_RAW_LIB at the decoder. Also in the archive: the license, the
third-party notices and the decoder's source, which the LGPL asks us to carry.
One command
cargo build --release in a checkout of the
repository makes both files in
target/release; add --features gpu,wgpu -p lapstack-cli for the
GPU paths, which are loaded at run time and need no CUDA toolkit to build.
Lightroom Classic plugin
Send the frames of a stack out of the catalog to the lapstack command-line tool and get
the stacked image back, imported and stacked above the first frame. Works as a Library
menu item and as an export target. It drives the command-line tool, so install that first.
The plugin is a zip in every release, and the folder lightroom/lapstack.lrplugin
in the repository.
The source
Everything above is built from one repository, under the MIT license: the engine, the command-line tool, the browser app, the desktop shell and the plugin, with the papers the algorithm comes from cited and every formula it implements written out in the README. Bug reports and patches are welcome there.
Or just open a tab
The browser app is not a teaser or a trial of anything — it is the whole application, running the same engine on your own GPU, with your images never leaving your machine. If it does what you need, the desktop build will mostly save you a browser setting.