diff --git a/.github/workflows/cd.yml b/.github/workflows/cd.yml
index ac6f1d771..25ae84250 100644
--- a/.github/workflows/cd.yml
+++ b/.github/workflows/cd.yml
@@ -144,4 +144,5 @@ jobs:
             --crate ../fj-kernel \
             --crate ../fj-math \
             --crate ../fj-operations \
+            --crate ../fj-viewer \
             --crate ../fj
diff --git a/Cargo.lock b/Cargo.lock
index e5611164b..660d0fb11 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -694,26 +694,17 @@ name = "fj-app"
 version = "0.5.0"
 dependencies = [
  "anyhow",
- "bytemuck",
  "clap",
  "figment",
  "fj",
  "fj-export",
  "fj-host",
- "fj-interop",
  "fj-kernel",
  "fj-math",
  "fj-operations",
- "futures",
- "nalgebra",
- "parry3d-f64",
+ "fj-viewer",
  "serde",
- "thiserror",
- "tracing",
  "tracing-subscriber",
- "wgpu",
- "wgpu_glyph",
- "winit",
 ]
 
 [[package]]
@@ -786,6 +777,25 @@ dependencies = [
  "parry3d-f64",
 ]
 
+[[package]]
+name = "fj-viewer"
+version = "0.5.0"
+dependencies = [
+ "bytemuck",
+ "fj-host",
+ "fj-interop",
+ "fj-math",
+ "fj-operations",
+ "futures",
+ "nalgebra",
+ "parry3d-f64",
+ "thiserror",
+ "tracing",
+ "wgpu",
+ "wgpu_glyph",
+ "winit",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.22"
diff --git a/Cargo.toml b/Cargo.toml
index 8cff3f60c..846e2fa61 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,7 @@ members = [
     "fj-kernel",
     "fj-math",
     "fj-operations",
+    "fj-viewer",
 
     "models/cuboid",
     "models/group",
@@ -25,4 +26,5 @@ default-members = [
     "fj-kernel",
     "fj-math",
     "fj-operations",
+    "fj-viewer",
 ]
diff --git a/fj-app/Cargo.toml b/fj-app/Cargo.toml
index 63ad7538c..6fad6b3cd 100644
--- a/fj-app/Cargo.toml
+++ b/fj-app/Cargo.toml
@@ -13,15 +13,6 @@ categories = ["mathematics", "rendering"]
 
 [dependencies]
 anyhow = "1.0.56"
-bytemuck = "1.9.1"
-futures = "0.3.21"
-nalgebra = "0.30.0"
-parry3d-f64 = "0.8.0"
-thiserror = "1.0.30"
-tracing = "0.1.33"
-wgpu = "0.12.0"
-wgpu_glyph = "0.16.0"
-winit = "0.26.1"
 
 [dependencies.clap]
 version = "3.1.8"
@@ -43,10 +34,6 @@ path = "../fj-export"
 version = "0.5.0"
 path = "../fj-host"
 
-[dependencies.fj-interop]
-version = "0.5.0"
-path = "../fj-interop"
-
 [dependencies.fj-kernel]
 version = "0.5.0"
 path = "../fj-kernel"
@@ -59,6 +46,10 @@ path = "../fj-math"
 version = "0.5.0"
 path = "../fj-operations"
 
+[dependencies.fj-viewer]
+version = "0.5.0"
+path = "../fj-viewer"
+
 [dependencies.serde]
 version = "1.0.136"
 features = ["derive"]
diff --git a/fj-app/src/main.rs b/fj-app/src/main.rs
index 9e770c87e..a252070c8 100644
--- a/fj-app/src/main.rs
+++ b/fj-app/src/main.rs
@@ -1,33 +1,17 @@
 mod args;
-mod camera;
 mod config;
-mod graphics;
-mod input;
-mod window;
 
 use std::path::PathBuf;
-use std::time::Instant;
 
 use anyhow::anyhow;
 use fj_export::export;
 use fj_host::{Model, Parameters};
 use fj_operations::shape_processor::ShapeProcessor;
-use futures::executor::block_on;
-use tracing::{trace, warn};
+use fj_viewer::run::run;
 use tracing_subscriber::fmt::format;
 use tracing_subscriber::EnvFilter;
-use winit::{
-    event::{Event, WindowEvent},
-    event_loop::{ControlFlow, EventLoop},
-};
 
-use crate::{
-    args::Args,
-    camera::Camera,
-    config::Config,
-    graphics::{DrawConfig, Renderer},
-    window::Window,
-};
+use crate::{args::Args, config::Config};
 
 fn main() -> anyhow::Result<()> {
     // Respect `RUST_LOG`. If that's not defined or erroneous, log warnings and
@@ -72,133 +56,7 @@ fn main() -> anyhow::Result<()> {
     }
 
     let watcher = model.load_and_watch(parameters)?;
+    run(watcher, shape_processor)?;
 
-    let event_loop = EventLoop::new();
-    let window = Window::new(&event_loop);
-
-    let mut previous_time = Instant::now();
-
-    let mut input_handler = input::Handler::new(previous_time);
-    let mut renderer = block_on(Renderer::new(&window))?;
-
-    let mut draw_config = DrawConfig::default();
-
-    let mut shape = None;
-    let mut camera = None;
-
-    event_loop.run(move |event, _, control_flow| {
-        trace!("Handling event: {:?}", event);
-
-        let mut actions = input::Actions::new();
-
-        let now = Instant::now();
-
-        if let Some(new_shape) = watcher.receive() {
-            let new_shape = shape_processor.process(&new_shape);
-            renderer.update_geometry(
-                (&new_shape.mesh).into(),
-                (&new_shape.debug_info).into(),
-                new_shape.aabb,
-            );
-
-            if camera.is_none() {
-                camera = Some(Camera::new(&new_shape.aabb));
-            }
-
-            shape = Some(new_shape);
-        }
-
-        match event {
-            Event::WindowEvent {
-                event: WindowEvent::CloseRequested,
-                ..
-            } => {
-                *control_flow = ControlFlow::Exit;
-            }
-            Event::WindowEvent {
-                event: WindowEvent::Resized(size),
-                ..
-            } => {
-                renderer.handle_resize(size);
-            }
-            Event::WindowEvent {
-                event: WindowEvent::KeyboardInput { input, .. },
-                ..
-            } => {
-                input_handler.handle_keyboard_input(input, &mut actions);
-            }
-            Event::WindowEvent {
-                event: WindowEvent::CursorMoved { position, .. },
-                ..
-            } => {
-                if let Some(camera) = &mut camera {
-                    input_handler
-                        .handle_cursor_moved(position, camera, &window);
-                }
-            }
-            Event::WindowEvent {
-                event: WindowEvent::MouseInput { state, button, .. },
-                ..
-            } => {
-                if let (Some(shape), Some(camera)) = (&shape, &camera) {
-                    let focus_point = camera.focus_point(
-                        &window,
-                        input_handler.cursor(),
-                        &shape.mesh,
-                    );
-
-                    input_handler.handle_mouse_input(
-                        button,
-                        state,
-                        focus_point,
-                    );
-                }
-            }
-            Event::WindowEvent {
-                event: WindowEvent::MouseWheel { delta, .. },
-                ..
-            } => {
-                input_handler.handle_mouse_wheel(delta, now);
-            }
-            Event::MainEventsCleared => {
-                let delta_t = now.duration_since(previous_time);
-                previous_time = now;
-
-                if let (Some(shape), Some(camera)) = (&shape, &mut camera) {
-                    input_handler.update(
-                        delta_t.as_secs_f64(),
-                        now,
-                        camera,
-                        &window,
-                        &shape.mesh,
-                    );
-                }
-
-                window.inner().request_redraw();
-            }
-            Event::RedrawRequested(_) => {
-                if let (Some(shape), Some(camera)) = (&shape, &mut camera) {
-                    camera.update_planes(&shape.aabb);
-
-                    if let Err(err) = renderer.draw(camera, &draw_config) {
-                        warn!("Draw error: {}", err);
-                    }
-                }
-            }
-            _ => {}
-        }
-
-        if actions.exit {
-            *control_flow = ControlFlow::Exit;
-        }
-        if actions.toggle_model {
-            draw_config.draw_model = !draw_config.draw_model;
-        }
-        if actions.toggle_mesh {
-            draw_config.draw_mesh = !draw_config.draw_mesh;
-        }
-        if actions.toggle_debug {
-            draw_config.draw_debug = !draw_config.draw_debug;
-        }
-    });
+    Ok(())
 }
diff --git a/fj-viewer/Cargo.toml b/fj-viewer/Cargo.toml
new file mode 100644
index 000000000..f3bbde29c
--- /dev/null
+++ b/fj-viewer/Cargo.toml
@@ -0,0 +1,39 @@
+[package]
+name = "fj-viewer"
+version = "0.5.0"
+edition = "2021"
+
+description = "The world needs another CAD program."
+readme = "../README.md"
+repository = "https://github.com/hannobraun/fornjot"
+license = "0BSD"
+keywords = ["cad", "programmatic", "code-cad"]
+categories = ["rendering"]
+
+
+[dependencies]
+bytemuck = "1.9.1"
+futures = "0.3.21"
+nalgebra = "0.30.0"
+parry3d-f64 = "0.8.0"
+thiserror = "1.0.30"
+tracing = "0.1.33"
+wgpu = "0.12.0"
+wgpu_glyph = "0.16.0"
+winit = "0.26.1"
+
+[dependencies.fj-host]
+version = "0.5.0"
+path = "../fj-host"
+
+[dependencies.fj-interop]
+version = "0.5.0"
+path = "../fj-interop"
+
+[dependencies.fj-math]
+version = "0.5.0"
+path = "../fj-math"
+
+[dependencies.fj-operations]
+version = "0.5.0"
+path = "../fj-operations"
diff --git a/fj-app/src/camera.rs b/fj-viewer/src/camera.rs
similarity index 100%
rename from fj-app/src/camera.rs
rename to fj-viewer/src/camera.rs
diff --git a/fj-app/src/graphics/config_ui.rs b/fj-viewer/src/graphics/config_ui.rs
similarity index 100%
rename from fj-app/src/graphics/config_ui.rs
rename to fj-viewer/src/graphics/config_ui.rs
diff --git a/fj-app/src/graphics/draw_config.rs b/fj-viewer/src/graphics/draw_config.rs
similarity index 100%
rename from fj-app/src/graphics/draw_config.rs
rename to fj-viewer/src/graphics/draw_config.rs
diff --git a/fj-app/src/graphics/drawables.rs b/fj-viewer/src/graphics/drawables.rs
similarity index 100%
rename from fj-app/src/graphics/drawables.rs
rename to fj-viewer/src/graphics/drawables.rs
diff --git a/fj-app/src/graphics/fonts/B612-Bold.ttf b/fj-viewer/src/graphics/fonts/B612-Bold.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612-Bold.ttf
rename to fj-viewer/src/graphics/fonts/B612-Bold.ttf
diff --git a/fj-app/src/graphics/fonts/B612-BoldItalic.ttf b/fj-viewer/src/graphics/fonts/B612-BoldItalic.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612-BoldItalic.ttf
rename to fj-viewer/src/graphics/fonts/B612-BoldItalic.ttf
diff --git a/fj-app/src/graphics/fonts/B612-Italic.ttf b/fj-viewer/src/graphics/fonts/B612-Italic.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612-Italic.ttf
rename to fj-viewer/src/graphics/fonts/B612-Italic.ttf
diff --git a/fj-app/src/graphics/fonts/B612-Regular.ttf b/fj-viewer/src/graphics/fonts/B612-Regular.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612-Regular.ttf
rename to fj-viewer/src/graphics/fonts/B612-Regular.ttf
diff --git a/fj-app/src/graphics/fonts/B612Mono-Bold.ttf b/fj-viewer/src/graphics/fonts/B612Mono-Bold.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612Mono-Bold.ttf
rename to fj-viewer/src/graphics/fonts/B612Mono-Bold.ttf
diff --git a/fj-app/src/graphics/fonts/B612Mono-BoldItalic.ttf b/fj-viewer/src/graphics/fonts/B612Mono-BoldItalic.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612Mono-BoldItalic.ttf
rename to fj-viewer/src/graphics/fonts/B612Mono-BoldItalic.ttf
diff --git a/fj-app/src/graphics/fonts/B612Mono-Italic.ttf b/fj-viewer/src/graphics/fonts/B612Mono-Italic.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612Mono-Italic.ttf
rename to fj-viewer/src/graphics/fonts/B612Mono-Italic.ttf
diff --git a/fj-app/src/graphics/fonts/B612Mono-Regular.ttf b/fj-viewer/src/graphics/fonts/B612Mono-Regular.ttf
similarity index 100%
rename from fj-app/src/graphics/fonts/B612Mono-Regular.ttf
rename to fj-viewer/src/graphics/fonts/B612Mono-Regular.ttf
diff --git a/fj-app/src/graphics/fonts/OFL.txt b/fj-viewer/src/graphics/fonts/OFL.txt
similarity index 100%
rename from fj-app/src/graphics/fonts/OFL.txt
rename to fj-viewer/src/graphics/fonts/OFL.txt
diff --git a/fj-app/src/graphics/geometries.rs b/fj-viewer/src/graphics/geometries.rs
similarity index 100%
rename from fj-app/src/graphics/geometries.rs
rename to fj-viewer/src/graphics/geometries.rs
diff --git a/fj-app/src/graphics/mod.rs b/fj-viewer/src/graphics/mod.rs
similarity index 85%
rename from fj-app/src/graphics/mod.rs
rename to fj-viewer/src/graphics/mod.rs
index 9e952ff81..573680aa4 100644
--- a/fj-app/src/graphics/mod.rs
+++ b/fj-viewer/src/graphics/mod.rs
@@ -11,7 +11,7 @@ mod vertices;
 
 pub use self::{
     draw_config::DrawConfig,
-    renderer::{DrawError, Renderer},
+    renderer::{DrawError, InitError, Renderer},
 };
 
 const DEPTH_FORMAT: wgpu::TextureFormat = wgpu::TextureFormat::Depth32Float;
diff --git a/fj-app/src/graphics/pipelines.rs b/fj-viewer/src/graphics/pipelines.rs
similarity index 100%
rename from fj-app/src/graphics/pipelines.rs
rename to fj-viewer/src/graphics/pipelines.rs
diff --git a/fj-app/src/graphics/renderer.rs b/fj-viewer/src/graphics/renderer.rs
similarity index 100%
rename from fj-app/src/graphics/renderer.rs
rename to fj-viewer/src/graphics/renderer.rs
diff --git a/fj-app/src/graphics/shader.wgsl b/fj-viewer/src/graphics/shader.wgsl
similarity index 100%
rename from fj-app/src/graphics/shader.wgsl
rename to fj-viewer/src/graphics/shader.wgsl
diff --git a/fj-app/src/graphics/shaders.rs b/fj-viewer/src/graphics/shaders.rs
similarity index 100%
rename from fj-app/src/graphics/shaders.rs
rename to fj-viewer/src/graphics/shaders.rs
diff --git a/fj-app/src/graphics/transform.rs b/fj-viewer/src/graphics/transform.rs
similarity index 100%
rename from fj-app/src/graphics/transform.rs
rename to fj-viewer/src/graphics/transform.rs
diff --git a/fj-app/src/graphics/uniforms.rs b/fj-viewer/src/graphics/uniforms.rs
similarity index 100%
rename from fj-app/src/graphics/uniforms.rs
rename to fj-viewer/src/graphics/uniforms.rs
diff --git a/fj-app/src/graphics/vertices.rs b/fj-viewer/src/graphics/vertices.rs
similarity index 100%
rename from fj-app/src/graphics/vertices.rs
rename to fj-viewer/src/graphics/vertices.rs
diff --git a/fj-app/src/input/handler.rs b/fj-viewer/src/input/handler.rs
similarity index 96%
rename from fj-app/src/input/handler.rs
rename to fj-viewer/src/input/handler.rs
index 42eca7824..3e28f1795 100644
--- a/fj-app/src/input/handler.rs
+++ b/fj-viewer/src/input/handler.rs
@@ -133,6 +133,7 @@ impl Handler {
     }
 }
 
+#[derive(Default)]
 pub struct Actions {
     pub exit: bool,
 
@@ -143,12 +144,6 @@ pub struct Actions {
 
 impl Actions {
     pub fn new() -> Self {
-        Self {
-            exit: false,
-
-            toggle_model: false,
-            toggle_mesh: false,
-            toggle_debug: false,
-        }
+        Self::default()
     }
 }
diff --git a/fj-app/src/input/mod.rs b/fj-viewer/src/input/mod.rs
similarity index 100%
rename from fj-app/src/input/mod.rs
rename to fj-viewer/src/input/mod.rs
diff --git a/fj-app/src/input/movement.rs b/fj-viewer/src/input/movement.rs
similarity index 100%
rename from fj-app/src/input/movement.rs
rename to fj-viewer/src/input/movement.rs
diff --git a/fj-app/src/input/rotation.rs b/fj-viewer/src/input/rotation.rs
similarity index 100%
rename from fj-app/src/input/rotation.rs
rename to fj-viewer/src/input/rotation.rs
diff --git a/fj-app/src/input/zoom.rs b/fj-viewer/src/input/zoom.rs
similarity index 100%
rename from fj-app/src/input/zoom.rs
rename to fj-viewer/src/input/zoom.rs
diff --git a/fj-viewer/src/lib.rs b/fj-viewer/src/lib.rs
new file mode 100644
index 000000000..672937437
--- /dev/null
+++ b/fj-viewer/src/lib.rs
@@ -0,0 +1,5 @@
+pub mod camera;
+pub mod graphics;
+pub mod input;
+pub mod run;
+pub mod window;
diff --git a/fj-viewer/src/run.rs b/fj-viewer/src/run.rs
new file mode 100644
index 000000000..1d5551ea7
--- /dev/null
+++ b/fj-viewer/src/run.rs
@@ -0,0 +1,151 @@
+use std::time::Instant;
+
+use fj_host::Watcher;
+use fj_operations::shape_processor::ShapeProcessor;
+use futures::executor::block_on;
+use tracing::{trace, warn};
+use winit::{
+    event::{Event, WindowEvent},
+    event_loop::{ControlFlow, EventLoop},
+};
+
+use crate::{
+    camera::Camera,
+    graphics::{self, DrawConfig, Renderer},
+    input,
+    window::Window,
+};
+
+pub fn run(
+    watcher: Watcher,
+    shape_processor: ShapeProcessor,
+) -> Result<(), graphics::InitError> {
+    let event_loop = EventLoop::new();
+    let window = Window::new(&event_loop);
+
+    let mut previous_time = Instant::now();
+
+    let mut input_handler = input::Handler::new(previous_time);
+    let mut renderer = block_on(Renderer::new(&window))?;
+
+    let mut draw_config = DrawConfig::default();
+
+    let mut shape = None;
+    let mut camera = None;
+
+    event_loop.run(move |event, _, control_flow| {
+        trace!("Handling event: {:?}", event);
+
+        let mut actions = input::Actions::new();
+
+        let now = Instant::now();
+
+        if let Some(new_shape) = watcher.receive() {
+            let new_shape = shape_processor.process(&new_shape);
+            renderer.update_geometry(
+                (&new_shape.mesh).into(),
+                (&new_shape.debug_info).into(),
+                new_shape.aabb,
+            );
+
+            if camera.is_none() {
+                camera = Some(Camera::new(&new_shape.aabb));
+            }
+
+            shape = Some(new_shape);
+        }
+
+        match event {
+            Event::WindowEvent {
+                event: WindowEvent::CloseRequested,
+                ..
+            } => {
+                *control_flow = ControlFlow::Exit;
+            }
+            Event::WindowEvent {
+                event: WindowEvent::Resized(size),
+                ..
+            } => {
+                renderer.handle_resize(size);
+            }
+            Event::WindowEvent {
+                event: WindowEvent::KeyboardInput { input, .. },
+                ..
+            } => {
+                input_handler.handle_keyboard_input(input, &mut actions);
+            }
+            Event::WindowEvent {
+                event: WindowEvent::CursorMoved { position, .. },
+                ..
+            } => {
+                if let Some(camera) = &mut camera {
+                    input_handler
+                        .handle_cursor_moved(position, camera, &window);
+                }
+            }
+            Event::WindowEvent {
+                event: WindowEvent::MouseInput { state, button, .. },
+                ..
+            } => {
+                if let (Some(shape), Some(camera)) = (&shape, &camera) {
+                    let focus_point = camera.focus_point(
+                        &window,
+                        input_handler.cursor(),
+                        &shape.mesh,
+                    );
+
+                    input_handler.handle_mouse_input(
+                        button,
+                        state,
+                        focus_point,
+                    );
+                }
+            }
+            Event::WindowEvent {
+                event: WindowEvent::MouseWheel { delta, .. },
+                ..
+            } => {
+                input_handler.handle_mouse_wheel(delta, now);
+            }
+            Event::MainEventsCleared => {
+                let delta_t = now.duration_since(previous_time);
+                previous_time = now;
+
+                if let (Some(shape), Some(camera)) = (&shape, &mut camera) {
+                    input_handler.update(
+                        delta_t.as_secs_f64(),
+                        now,
+                        camera,
+                        &window,
+                        &shape.mesh,
+                    );
+                }
+
+                window.inner().request_redraw();
+            }
+            Event::RedrawRequested(_) => {
+                if let (Some(shape), Some(camera)) = (&shape, &mut camera) {
+                    camera.update_planes(&shape.aabb);
+
+                    if let Err(err) = renderer.draw(camera, &draw_config) {
+                        warn!("Draw error: {}", err);
+                    }
+                }
+            }
+            _ => {}
+        }
+
+        if actions.exit {
+            *control_flow = ControlFlow::Exit;
+        }
+        if actions.toggle_model {
+            draw_config.draw_model = !draw_config.draw_model;
+        }
+        if actions.toggle_mesh {
+            draw_config.draw_mesh = !draw_config.draw_mesh;
+        }
+        if actions.toggle_debug {
+            draw_config.draw_debug = !draw_config.draw_debug;
+        }
+    });
+}
diff --git a/fj-app/src/window.rs b/fj-viewer/src/window.rs
similarity index 100%
rename from fj-app/src/window.rs
rename to fj-viewer/src/window.rs