diff --git a/.github/workflows/constraints-demo.yml b/.github/workflows/constraints-demo.yml
index 1efbd88c..e2f7cf02 100644
--- a/.github/workflows/constraints-demo.yml
+++ b/.github/workflows/constraints-demo.yml
@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     defaults:
       run:
-        working-directory: ./constraints
+        working-directory: ./demos/constraints
     steps:
     - uses: actions/checkout@v4
     - uses: Swatinem/rust-cache@v2
diff --git a/.github/workflows/wasm-demo.yml b/.github/workflows/wasm-demo.yml
index b2f02306..2364d79b 100644
--- a/.github/workflows/wasm-demo.yml
+++ b/.github/workflows/wasm-demo.yml
@@ -14,14 +14,15 @@ jobs:
     runs-on: ubuntu-latest
     defaults:
       run:
-        working-directory: ./wasm-demo
+        working-directory: ./demos/web-editor
     steps:
     - uses: actions/checkout@v4
     - uses: Swatinem/rust-cache@v2
     - name: Install wasm target
       run: rustup target add wasm32-unknown-unknown
     - name: Install wasm-pack
-      run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+      run: |
+        curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
     - name: Install npm dependencies
       run: npm install
     - name: Check Prettier
diff --git a/Cargo.lock b/Cargo.lock
index 4eb8c2f3..10a844ab 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -634,20 +634,6 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "96a6ac251f4a2aca6b3f91340350eab87ae57c3f127ffeb585e92bd336717991"
 
-[[package]]
-name = "demo"
-version = "0.1.0"
-dependencies = [
- "anyhow",
- "clap",
- "env_logger 0.11.2",
- "fidget",
- "image",
- "log",
- "nalgebra",
- "workspace-hack",
-]
-
 [[package]]
 name = "dispatch"
 version = "0.2.0"
@@ -915,6 +901,37 @@ dependencies = [
  "workspace-hack",
 ]
 
+[[package]]
+name = "fidget-cli"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "clap",
+ "env_logger 0.11.2",
+ "fidget",
+ "image",
+ "log",
+ "nalgebra",
+ "workspace-hack",
+]
+
+[[package]]
+name = "fidget-viewer"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "clap",
+ "crossbeam-channel",
+ "eframe",
+ "env_logger 0.10.2",
+ "fidget",
+ "log",
+ "nalgebra",
+ "notify",
+ "rhai",
+ "workspace-hack",
+]
+
 [[package]]
 name = "filetime"
 version = "0.2.23"
@@ -2379,23 +2396,6 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
-[[package]]
-name = "viewer"
-version = "0.1.0"
-dependencies = [
- "anyhow",
- "clap",
- "crossbeam-channel",
- "eframe",
- "env_logger 0.10.2",
- "fidget",
- "log",
- "nalgebra",
- "notify",
- "rhai",
- "workspace-hack",
-]
-
 [[package]]
 name = "walkdir"
 version = "2.4.0"
diff --git a/Cargo.toml b/Cargo.toml
index 044fd375..8d3ef956 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,12 +2,12 @@
 resolver = "2"
 members = [
     "fidget",
-    "constraints",
-    "demo",
-    "viewer",
+    "demos/constraints",
+    "demos/cli",
+    "demos/viewer",
     "workspace-hack",
 ]
-exclude = ["wasm-demo"]
+exclude = ["demos/web-editor"]
 
 [profile.release]
 debug = true
diff --git a/README.md b/README.md
index 5f98aa5e..26bf4c42 100644
--- a/README.md
+++ b/README.md
@@ -51,31 +51,10 @@ Issues and PRs are welcome, although I'm unlikely to merge anything which adds
 substantial maintenance burden.  This is a personal-scale experimental project,
 so adjust your expectations accordingly.
 
-## Demo applications
-In the [repository on Github](https://github.com/mkeeter/fidget), there are
-two demo applications:
-
-- `demo` does bitmap rendering and meshing from the command line
-- `viewer` is a minimal GUI for interactive exploration
-
-These are deliberately not published to [https://crates.io](crates.io), because
-they're demo applications and not complete end-user tools.
-
-## WebAssembly demo
-The `wasm-demo` subfolder embeds Fidget into a web application.  Building this
-demo requires [`wasm-pack`](https://rustwasm.github.io/wasm-pack/)
-to be installed on the host system.
-
-In that folder, run it with
-```
-npm install
-npm run serve
-```
-
-Or bundle files for distribution with
-```
-npm run build
-```
+## Demos
+The [`demos` folder](demos/README.md) contains several demo tools and
+applications built using the Fidget crate,
+ranging from CLI to GUI to web app.
 
 ## Support matrix
 At the moment, Fidget supports a limited number of platforms:
diff --git a/demos/.gitignore b/demos/.gitignore
new file mode 100644
index 00000000..557a5559
--- /dev/null
+++ b/demos/.gitignore
@@ -0,0 +1 @@
+!*/screenshot.png
diff --git a/demos/README.md b/demos/README.md
new file mode 100644
index 00000000..4d9928b9
--- /dev/null
+++ b/demos/README.md
@@ -0,0 +1,41 @@
+# Fidget demos
+## Command-line demo ([`cli`](cli/))
+
+Bitmap rendering and meshing from the command line
+```shell
+$ cargo run -pfidget-cli --release -- -i models/prospero.vm render2d -s512 --eval=vm -oout.png
+    Finished release [optimized + debuginfo] target(s) in 0.07s
+     Running `target/release/fidget-cli -i models/prospero.vm render2d -s512 --eval=vm -oout.png`
+[2024-06-06T16:08:12Z INFO  fidget_cli] Loaded file in 4.528208ms
+[2024-06-06T16:08:12Z INFO  fidget_cli] Built shape in 2.375208ms
+[2024-06-06T16:08:12Z INFO  fidget_cli] Rendered 1x at 14.489 ms/frame
+```
+
+## Script viewer ([`viewer`](viewer/))
+Minimal desktop GUI for interactive exploration,
+using [`egui`](https://github.com/emilk/egui)
+
+```shell
+cargo run --release -pfidget-viewer
+```
+
+![screenshot of script viewer](viewer/screenshot.png)
+
+## Constraint solving ([`constraints`](constraints/))
+Example of using Fidget for constraint solving.
+Uses [`egui`](https://github.com/emilk/egui)
+and runs either on the desktop or as a web app.
+```shell
+cargo run --release -pconstraints
+```
+
+![screenshot of contraint editor](constraints/screenshot.png)
+
+See the [subfolder](constraints/) for details on bundling for the web.
+
+## Web-based editor ([`web-editor`](web-editor/))
+Integrates Fidget into a TypeScript project (web only)
+
+![screenshot of web editor](web-editor/screenshot.png)
+
+See the [subfolder](web-editor/) for details on bundling for the web.
diff --git a/demo/Cargo.toml b/demos/cli/Cargo.toml
similarity index 62%
rename from demo/Cargo.toml
rename to demos/cli/Cargo.toml
index ea76b6bb..03713cf2 100644
--- a/demo/Cargo.toml
+++ b/demos/cli/Cargo.toml
@@ -1,10 +1,10 @@
 [package]
-name = "demo"
+name = "fidget-cli"
 version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-fidget = { path = "../fidget", default-features = false, features = ["render", "mesh"] }
+fidget = { path = "../../fidget", default-features = false, features = ["render", "mesh"] }
 
 anyhow = "1"
 clap = { version = "4", features = ["derive"] }
@@ -12,7 +12,7 @@ env_logger = "0.11.2"
 image = { version = "0.24", default-features = false, features = ["png"] }
 log = "0.4"
 nalgebra = "0.31"
-workspace-hack = { version = "0.1", path = "../workspace-hack" }
+workspace-hack = { version = "0.1", path = "../../workspace-hack" }
 
 [features]
 jit = ["fidget/jit"]
diff --git a/demo/src/main.rs b/demos/cli/src/main.rs
similarity index 100%
rename from demo/src/main.rs
rename to demos/cli/src/main.rs
diff --git a/constraints/.gitignore b/demos/constraints/.gitignore
similarity index 100%
rename from constraints/.gitignore
rename to demos/constraints/.gitignore
diff --git a/constraints/Cargo.toml b/demos/constraints/Cargo.toml
similarity index 75%
rename from constraints/Cargo.toml
rename to demos/constraints/Cargo.toml
index 05559a60..9b437f7b 100644
--- a/constraints/Cargo.toml
+++ b/demos/constraints/Cargo.toml
@@ -10,9 +10,9 @@ eframe = { version = "0.27", default-features = false, features = [
     "glow",          # Use the glow rendering backend. Alternative: "wgpu".
 ] }
 
-fidget = { path = "../fidget", default-features = false, features = ["solver"] }
+fidget = { path = "../../fidget", default-features = false, features = ["solver"] }
 log = "0.4"
-workspace-hack = { version = "0.1", path = "../workspace-hack" }
+workspace-hack = { version = "0.1", path = "../../workspace-hack" }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 env_logger = "0.10.0"
diff --git a/constraints/README.md b/demos/constraints/README.md
similarity index 85%
rename from constraints/README.md
rename to demos/constraints/README.md
index 84d0ebf0..259e2d4c 100644
--- a/constraints/README.md
+++ b/demos/constraints/README.md
@@ -1,8 +1,9 @@
 # Demo of constraint solving
 ## WebAssembly
 ### Setup
+Install the [`trunk`](https://trunkrs.dev/) bundler with
 ```
-cargon install +locked trunk # installs the `trunk` bundler
+cargo install +locked trunk
 ```
 ### Developing
 In this folder, run
diff --git a/constraints/index.html b/demos/constraints/index.html
similarity index 100%
rename from constraints/index.html
rename to demos/constraints/index.html
diff --git a/demos/constraints/screenshot.png b/demos/constraints/screenshot.png
new file mode 100644
index 00000000..3e75aa9b
Binary files /dev/null and b/demos/constraints/screenshot.png differ
diff --git a/constraints/src/main.rs b/demos/constraints/src/main.rs
similarity index 100%
rename from constraints/src/main.rs
rename to demos/constraints/src/main.rs
diff --git a/viewer/Cargo.toml b/demos/viewer/Cargo.toml
similarity index 76%
rename from viewer/Cargo.toml
rename to demos/viewer/Cargo.toml
index 083b5b9f..7cc00a71 100644
--- a/viewer/Cargo.toml
+++ b/demos/viewer/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "viewer"
+name = "fidget-viewer"
 version = "0.1.0"
 edition = "2021"
 
@@ -15,12 +15,12 @@ eframe = { version = "0.27", default-features = false, features = [
 ] }
 env_logger = "0.10.0"
 
-fidget = { path = "../fidget", default-features = false, features = ["render", "rhai"] }
+fidget = { path = "../../fidget", default-features = false, features = ["render", "rhai"] }
 log = "0.4"
 nalgebra = "0.31"
 notify = "5.0"
 rhai = "1.10"
-workspace-hack = { version = "0.1", path = "../workspace-hack" }
+workspace-hack = { version = "0.1", path = "../../workspace-hack" }
 
 [features]
 default = ["jit"]
diff --git a/demos/viewer/screenshot.png b/demos/viewer/screenshot.png
new file mode 100644
index 00000000..6abef16c
Binary files /dev/null and b/demos/viewer/screenshot.png differ
diff --git a/viewer/src/main.rs b/demos/viewer/src/main.rs
similarity index 100%
rename from viewer/src/main.rs
rename to demos/viewer/src/main.rs
diff --git a/wasm-demo/.gitignore b/demos/web-editor/.gitignore
similarity index 100%
rename from wasm-demo/.gitignore
rename to demos/web-editor/.gitignore
diff --git a/wasm-demo/Cargo.lock b/demos/web-editor/Cargo.lock
similarity index 100%
rename from wasm-demo/Cargo.lock
rename to demos/web-editor/Cargo.lock
diff --git a/wasm-demo/Cargo.toml b/demos/web-editor/Cargo.toml
similarity index 75%
rename from wasm-demo/Cargo.toml
rename to demos/web-editor/Cargo.toml
index fa231c85..fca51b5e 100644
--- a/wasm-demo/Cargo.toml
+++ b/demos/web-editor/Cargo.toml
@@ -8,7 +8,7 @@ crate-type = ["cdylib"]
 
 [dependencies]
 bincode = "1.3.3"
-fidget = {path = "../fidget", default-features = false, features = ["rhai", "mesh", "render"]}
+fidget = {path = "../../fidget", default-features = false, features = ["rhai", "mesh", "render"]}
 wasm-bindgen = "0.2.92"
 nalgebra = "0.31"
 
diff --git a/demos/web-editor/README.md b/demos/web-editor/README.md
new file mode 100644
index 00000000..a705d40d
--- /dev/null
+++ b/demos/web-editor/README.md
@@ -0,0 +1,17 @@
+The `web-editor` subfolder embeds Fidget into a web application.
+
+Building this demo requires [`wasm-pack`](https://rustwasm.github.io/wasm-pack/)
+to be installed on the host system.
+
+Run the editor demo with
+
+```
+npm install
+npm run serve
+```
+
+Or bundle files for distribution with
+
+```
+npm run build
+```
diff --git a/wasm-demo/constants.ts b/demos/web-editor/constants.ts
similarity index 100%
rename from wasm-demo/constants.ts
rename to demos/web-editor/constants.ts
diff --git a/wasm-demo/index.html b/demos/web-editor/index.html
similarity index 100%
rename from wasm-demo/index.html
rename to demos/web-editor/index.html
diff --git a/wasm-demo/index.ts b/demos/web-editor/index.ts
similarity index 100%
rename from wasm-demo/index.ts
rename to demos/web-editor/index.ts
diff --git a/wasm-demo/message.ts b/demos/web-editor/message.ts
similarity index 100%
rename from wasm-demo/message.ts
rename to demos/web-editor/message.ts
diff --git a/wasm-demo/package-lock.json b/demos/web-editor/package-lock.json
similarity index 100%
rename from wasm-demo/package-lock.json
rename to demos/web-editor/package-lock.json
diff --git a/wasm-demo/package.json b/demos/web-editor/package.json
similarity index 100%
rename from wasm-demo/package.json
rename to demos/web-editor/package.json
diff --git a/demos/web-editor/screenshot.png b/demos/web-editor/screenshot.png
new file mode 100644
index 00000000..dc709324
Binary files /dev/null and b/demos/web-editor/screenshot.png differ
diff --git a/wasm-demo/src/lib.rs b/demos/web-editor/src/lib.rs
similarity index 100%
rename from wasm-demo/src/lib.rs
rename to demos/web-editor/src/lib.rs
diff --git a/wasm-demo/tsconfig.json b/demos/web-editor/tsconfig.json
similarity index 100%
rename from wasm-demo/tsconfig.json
rename to demos/web-editor/tsconfig.json
diff --git a/wasm-demo/webpack.config.js b/demos/web-editor/webpack.config.js
similarity index 100%
rename from wasm-demo/webpack.config.js
rename to demos/web-editor/webpack.config.js
diff --git a/wasm-demo/worker.ts b/demos/web-editor/worker.ts
similarity index 100%
rename from wasm-demo/worker.ts
rename to demos/web-editor/worker.ts
diff --git a/fidget/src/rhai/core.rhai b/fidget/src/rhai/core.rhai
index 44dd8f2a..cb9615f5 100644
--- a/fidget/src/rhai/core.rhai
+++ b/fidget/src/rhai/core.rhai
@@ -25,7 +25,7 @@ fn intersection(a, b) {
 }
 
 fn inverse(a) {
-    a.neg()
+    -a
 }
 
 fn difference(a, b) {