-This work may be reproduced, modified, distributed, performed, and displayed for any purpose. Copyright is retained and must be preserved. The work is provided as is; no warranty is provided, and users accept all liability.
+## Building
+
+The only dependency for `fstl` is [Qt 5](https://www.qt.io),
+plus [`cmake`](https://cmake.org/) for building.
+
+### macOS
+
+Install Qt from their website or [Homebrew](brew.sh).
+
+Install `cmake` through Homebrew or equivalent.
+
+Then, run through the following set of commands in a shell:
+
+```
+git clone https://github.com/fstl-app/fstl
+cd fstl
+mkdir build
+cd build
+cmake -DCMAKE_PREFIX_PATH=/usr/local/Cellar/qt/5.15.0/ ..
+make -j8
+./fstl.app/Contents/MacOS/fstl
+```
+
+You may need to edit the Qt path depending on your installation.
+
+To package a standalone app, go to the app directory and run `package.sh`
+
+```
+cd ../app
+./package.sh
+```
+
+This should produce two new files in the root directory:
+- `fstl.app` is a standalone application that can be copied to `/Applications`
+- `fstl.dmg` is a disk image that can be given to a friend
+
+### Linux
+
+Install Qt with your distro's package manager (required libraries are Core, Gui,
+Widgets and OpenGL, e.g. `qt5-default` and `libqt5opengl5-dev` on Debian).
+
+You can build fstl with CMake:
+```
+git clone https://github.com/fstl-app/fstl
+cd fstl
+mkdir build
+cd build
+cmake ..
+make -j8
+./fstl
+```