diff --git a/component-model/book.toml b/component-model/book.toml
index 74f0eaf2..bc2d8be5 100644
--- a/component-model/book.toml
+++ b/component-model/book.toml
@@ -8,7 +8,8 @@ title = "The WebAssembly Component Model"
 [output.html]
 git-repository-url = "https://github.com/bytecodealliance/component-docs/tree/main/component-model"
 edit-url-template = "https://github.com/bytecodealliance/component-docs/tree/main/component-model/{path}"
-additional-css = ["theme/head.hbs"]
+additional-css = ["theme/head.hbs", "theme/tabs.css", "theme/tabs-overrides.css", "theme/version-notice.css"]
+additional-js = ["theme/tabs.js", "theme/tabs-url-sync.js", "theme/tabs-a11y.js"]
 
 [output.html.fold]
 enable = true
@@ -34,4 +35,6 @@ level = 1
 
 [preprocessor.alerts]
 
+[preprocessor.tabs]
+
 [output.linkcheck]
diff --git a/component-model/src/running-components/wasmtime.md b/component-model/src/running-components/wasmtime.md
index 4272725c..79bb781d 100644
--- a/component-model/src/running-components/wasmtime.md
+++ b/component-model/src/running-components/wasmtime.md
@@ -1,9 +1,25 @@
 # Wasmtime
 
+<div class="version-notice">
+
+This page has content for both **WASI P2** and **WASI P3**. Use the tabs below to switch between versions where they differ.
+
+</div>
+
+{{#tabs global="wasi-version" }}
+{{#tab name="WASI P2" }}
 [Wasmtime](https://github.com/bytecodealliance/wasmtime/) is the reference implementation of the Component Model.
-It supports running components that implement the [`wasi:cli/command` world](https://github.com/WebAssembly/wasi-cli/blob/main/wit/command.wit)
-and serving components that implement the [`wasi:http/proxy` world](https://github.com/WebAssembly/wasi-http/blob/main/wit/proxy.wit).
+It supports running components that implement the [`wasi:cli/command` world](https://github.com/WebAssembly/WASI/blob/main/proposals/cli/wit/command.wit)
+and serving components that implement the [`wasi:http/proxy` world](https://github.com/WebAssembly/WASI/blob/main/proposals/http/wit/proxy.wit).
 Wasmtime can also invoke functions exported from a component.
+{{#endtab }}
+{{#tab name="WASI P3" }}
+[Wasmtime](https://github.com/bytecodealliance/wasmtime/) is the reference implementation of the Component Model. WASI P3 runtime support is available in Wasmtime 43 and later, which implements the WASI 0.3 ABI (`async func`, `stream<T>`, `future<T>`).
+
+It supports running components that implement the [`wasi:cli/command` world](https://github.com/WebAssembly/WASI/blob/main/proposals/cli/wit-0.3.0-draft/command.wit). Support for serving components in the [`wasi:http/service` world](https://github.com/WebAssembly/WASI/blob/main/proposals/http/wit-0.3.0-draft/worlds.wit) and the new [`wasi:http/middleware` world](https://github.com/WebAssembly/WASI/blob/main/proposals/http/wit-0.3.0-draft/worlds.wit), which both imports and exports the HTTP handler interface, is in development. See [the tracking issue](https://github.com/bytecodealliance/wit-bindgen/issues/1554) for current status.
+Wasmtime can also invoke functions exported from a component.
+{{#endtab }}
+{{#endtabs }}
 
 ## Running command components with Wasmtime
 To run a command component with Wasmtime, execute:
@@ -21,8 +37,10 @@ See the [Wasmtime guide](https://docs.wasmtime.dev/) for information on granting
 
 ## Running HTTP components with Wasmtime
 
-You can execute components that implement the [HTTP proxy world](https://github.com/WebAssembly/wasi-http/blob/main/wit/proxy.wit) with the `wasmtime serve` subcommand.
-[The Wasmtime CLI](https://github.com/bytecodealliance/wasmtime) supports serving these components as of `v14.0.3`.
+{{#tabs global="wasi-version" }}
+{{#tab name="WASI P2" }}
+You can execute components that implement the [HTTP proxy world](https://github.com/WebAssembly/WASI/blob/main/proposals/http/wit/proxy.wit) with the `wasmtime serve` subcommand.
+[The Wasmtime CLI](https://github.com/bytecodealliance/wasmtime) supports serving these components as of `v18.0.0`.
 
 To run a HTTP component with Wasmtime, execute:
 ```sh
@@ -34,6 +52,13 @@ Try out building and running HTTP components with one of these tutorials
 1. [Hello WASI HTTP tutorial](https://github.com/sunfishcode/hello-wasi-http) - build and serve a simple Rust-based HTTP component
 
 2. [HTTP Auth Middleware tutorial](https://github.com/fermyon/http-auth-middleware#running-with-wasmtime) - compose a HTTP authentication middleware component with a business logic component
+{{#endtab }}
+{{#tab name="WASI P3" }}
+Wasmtime 43 and later provide runtime support for the WASI P3 ABI. The `wasmtime serve` subcommand currently targets the [`wasi:http/proxy` world](https://github.com/WebAssembly/WASI/blob/main/proposals/http/wit/proxy.wit) from WASI P2; support for serving components in the WASI P3 [`wasi:http/service`](https://github.com/WebAssembly/WASI/blob/main/proposals/http/wit-0.3.0-draft/worlds.wit) and [`wasi:http/middleware`](https://github.com/WebAssembly/WASI/blob/main/proposals/http/wit-0.3.0-draft/worlds.wit) worlds is in progress. See [the tracking issue](https://github.com/bytecodealliance/wit-bindgen/issues/1554) for current status.
+
+For an overview of the WASI P3 HTTP interfaces, see [WASI 0.3](https://wasi.dev/releases/wasi-p3) on WASI.dev.
+{{#endtab }}
+{{#endtabs }}
 
 ## Running components with custom exports
 
diff --git a/component-model/theme/tabs-a11y.js b/component-model/theme/tabs-a11y.js
new file mode 100644
index 00000000..9c00303a
--- /dev/null
+++ b/component-model/theme/tabs-a11y.js
@@ -0,0 +1,114 @@
+(function () {
+    'use strict';
+
+    // Layer ARIA semantics and keyboard navigation onto the mdbook-tabs
+    // plugin's markup. The plugin emits plain <button> / <div> elements
+    // without tab/tablist/tabpanel roles; this script fills that gap.
+
+    let uidCounter = 0;
+    function nextUid() {
+        uidCounter += 1;
+        return uidCounter;
+    }
+
+    function initContainer(container) {
+        const nav = container.querySelector('.mdbook-tabs');
+        if (nav && !nav.hasAttribute('role')) {
+            nav.setAttribute('role', 'tablist');
+        }
+
+        const tabs = Array.from(container.querySelectorAll('.mdbook-tab'));
+        const panes = Array.from(container.querySelectorAll('.mdbook-tab-content'));
+
+        tabs.forEach(function (tab) {
+            if (tab.hasAttribute('role')) return;
+            const uid = nextUid();
+            const tabId = 'mdbook-tab-' + uid;
+            const paneId = 'mdbook-tabpanel-' + uid;
+
+            tab.setAttribute('role', 'tab');
+            tab.id = tabId;
+
+            const pane = panes.find(function (p) {
+                return p.dataset.tabname === tab.dataset.tabname;
+            });
+            if (pane) {
+                pane.setAttribute('role', 'tabpanel');
+                pane.id = paneId;
+                if (!pane.hasAttribute('tabindex')) {
+                    pane.setAttribute('tabindex', '0');
+                }
+                tab.setAttribute('aria-controls', paneId);
+                pane.setAttribute('aria-labelledby', tabId);
+            }
+        });
+    }
+
+    function syncContainer(container) {
+        container.querySelectorAll('.mdbook-tab').forEach(function (tab) {
+            const isActive = tab.classList.contains('active');
+            tab.setAttribute('aria-selected', isActive ? 'true' : 'false');
+            // Roving tabindex: only the active tab is reachable via Tab key;
+            // arrow keys move focus within the tablist.
+            tab.setAttribute('tabindex', isActive ? '0' : '-1');
+        });
+        container.querySelectorAll('.mdbook-tab-content').forEach(function (pane) {
+            pane.setAttribute('aria-hidden', pane.classList.contains('hidden') ? 'true' : 'false');
+        });
+    }
+
+    function syncAll() {
+        document.querySelectorAll('.mdbook-tabs-container').forEach(syncContainer);
+    }
+
+    function handleKeyDown(event) {
+        const tab = event.target.closest && event.target.closest('.mdbook-tab');
+        if (!tab) return;
+        const nav = tab.parentElement;
+        if (!nav || !nav.classList.contains('mdbook-tabs')) return;
+
+        const tabs = Array.from(nav.querySelectorAll('.mdbook-tab'));
+        const currentIndex = tabs.indexOf(tab);
+        if (currentIndex < 0) return;
+
+        let newIndex = null;
+        switch (event.key) {
+            case 'ArrowRight':
+            case 'Right':
+                newIndex = (currentIndex + 1) % tabs.length;
+                break;
+            case 'ArrowLeft':
+            case 'Left':
+                newIndex = (currentIndex - 1 + tabs.length) % tabs.length;
+                break;
+            case 'Home':
+                newIndex = 0;
+                break;
+            case 'End':
+                newIndex = tabs.length - 1;
+                break;
+        }
+        if (newIndex === null) return;
+
+        event.preventDefault();
+        tabs[newIndex].focus();
+        // Automatic activation: mirrors common tab widgets (Bootstrap, Radix,
+        // etc.) where focusing a tab also selects it.
+        tabs[newIndex].click();
+    }
+
+    document.addEventListener('DOMContentLoaded', function () {
+        document.querySelectorAll('.mdbook-tabs-container').forEach(initContainer);
+        syncAll();
+
+        document.addEventListener('keydown', handleKeyDown);
+
+        // Re-sync ARIA state after every click. Clicks may propagate across
+        // multiple containers when a global="..." state is shared, so we
+        // resync every container, not just the one that was clicked.
+        document.addEventListener('click', function (event) {
+            if (!event.target.closest || !event.target.closest('.mdbook-tab')) return;
+            syncAll();
+        });
+    });
+})();
diff --git a/component-model/theme/tabs-overrides.css b/component-model/theme/tabs-overrides.css
new file mode 100644
index 00000000..e1feff04
--- /dev/null
+++ b/component-model/theme/tabs-overrides.css
@@ -0,0 +1,68 @@
+/* Custom overrides to the mdbook-tabs plugin's default styling.
+   Kept separate from theme/tabs.css so plugin updates (via
+   `mdbook-tabs install`) do not overwrite these rules. */
+
+/* Container: left rail marking version-specific content. */
+.mdbook-tabs-container {
+    border-left: 3px solid var(--sidebar-active, var(--table-border-color));
+    padding-left: 1.25rem;
+}
+
+/* Nav: thin baseline below the tab row. */
+.mdbook-tabs {
+    border-bottom: 1px solid var(--table-border-color);
+}
+
+/* Tab button: explicit foreground color and transparent active
+   indicator so hover and active states have somewhere to land. */
+.mdbook-tab {
+    color: var(--fg);
+    border-bottom: 2px solid transparent;
+}
+
+@media (prefers-reduced-motion: no-preference) {
+    .mdbook-tab {
+        transition: color 120ms ease, border-color 120ms ease;
+    }
+}
+
+.mdbook-tab:hover:not(.active) {
+    color: var(--sidebar-active, var(--fg));
+}
+
+.mdbook-tab.active {
+    color: var(--sidebar-active, var(--fg));
+    border-bottom-color: var(--sidebar-active, var(--fg));
+}
+
+/* Rust theme: --sidebar-active (#e69f67) has low contrast against the
+   warm tan tab backgrounds. Fall back to --fg for the label text; the
+   accent still carries the active signal via the bottom border. */
+.rust .mdbook-tab.active {
+    color: var(--fg);
+}
+
+.rust .mdbook-tab:hover:not(.active) {
+    color: var(--fg);
+    border-bottom-color: var(--sidebar-active, var(--fg));
+}
+
+/* Print: show every tab pane with a heading-like label, and hide the
+   interactive nav since clicking has no meaning on paper. */
+@media print {
+    .mdbook-tabs {
+        display: none;
+    }
+
+    .mdbook-tab-content.hidden {
+        display: block;
+    }
+
+    .mdbook-tab-content::before {
+        content: attr(data-tabname);
+        display: block;
+        font-size: 1.3em;
+        font-weight: bold;
+        margin: 1em 0 0.5em;
+    }
+}
diff --git a/component-model/theme/tabs-url-sync.js b/component-model/theme/tabs-url-sync.js
new file mode 100644
index 00000000..e9e660f9
--- /dev/null
+++ b/component-model/theme/tabs-url-sync.js
@@ -0,0 +1,75 @@
+(function () {
+    'use strict';
+
+    const GLOBAL_NAME = 'wasi-version';
+    const PARAM_NAME = 'wasi';
+    const SLUG_TO_NAME = { p2: 'WASI P2', p3: 'WASI P3' };
+    const NAME_TO_SLUG = { 'WASI P2': 'p2', 'WASI P3': 'p3' };
+
+    function readSlugFromUrl() {
+        const value = new URLSearchParams(window.location.search).get(PARAM_NAME);
+        return value && SLUG_TO_NAME[value] ? value : null;
+    }
+
+    function writeSlugToUrl(slug) {
+        const url = new URL(window.location.href);
+        url.searchParams.set(PARAM_NAME, slug);
+        history.replaceState(null, '', url.toString());
+    }
+
+    function activateByName(name) {
+        const tab = document.querySelector(
+            '.mdbook-tabs-container[data-tabglobal="' + GLOBAL_NAME + '"] ' +
+            '.mdbook-tab[data-tabname="' + name + '"]'
+        );
+        if (tab) {
+            tab.click();
+        }
+    }
+
+    // If `element` lives inside a tab pane, activate that pane's tab.
+    // Returns true if a tab was activated.
+    function activateTabContainingElement(element) {
+        const pane = element.closest && element.closest('.mdbook-tab-content');
+        if (!pane) return false;
+        const container = pane.closest('.mdbook-tabs-container');
+        if (!container) return false;
+        const name = pane.dataset.tabname;
+        if (!name) return false;
+        const tab = container.querySelector('.mdbook-tab[data-tabname="' + name + '"]');
+        if (!tab) return false;
+        tab.click();
+        return true;
+    }
+
+    document.addEventListener('DOMContentLoaded', function () {
+        // Apply URL-param tab selection first.
+        const slug = readSlugFromUrl();
+        if (slug) {
+            activateByName(SLUG_TO_NAME[slug]);
+        }
+
+        // If the page was loaded with a hash pointing to an element inside a
+        // hidden tab pane, activate that pane and re-scroll. Hash wins over
+        // the ?wasi= param since the hash targets a specific element.
+        if (window.location.hash.length > 1) {
+            const targetId = decodeURIComponent(window.location.hash.slice(1));
+            const target = document.getElementById(targetId);
+            if (target && activateTabContainingElement(target)) {
+                target.scrollIntoView();
+            }
+        }
+
+        // Reflect wasi-version tab clicks back into the URL.
+        document.addEventListener('click', function (event) {
+            const tab = event.target.closest && event.target.closest('.mdbook-tab');
+            if (!tab) return;
+            const container = tab.closest('.mdbook-tabs-container');
+            if (!container || container.dataset.tabglobal !== GLOBAL_NAME) return;
+            const newSlug = NAME_TO_SLUG[tab.dataset.tabname];
+            if (newSlug) {
+                writeSlugToUrl(newSlug);
+            }
+        });
+    });
+})();
diff --git a/component-model/theme/tabs.css b/component-model/theme/tabs.css
new file mode 100644
index 00000000..8712b859
--- /dev/null
+++ b/component-model/theme/tabs.css
@@ -0,0 +1,25 @@
+.mdbook-tabs {
+    display: flex;
+}
+
+.mdbook-tab {
+    background-color: var(--table-alternate-bg);
+    padding: 0.5rem 1rem;
+    cursor: pointer;
+    border: none;
+    font-size: 1.6rem;
+    line-height: 1.45em;
+}
+
+.mdbook-tab.active {
+    background-color: var(--table-header-bg);
+    font-weight: bold;
+}
+
+.mdbook-tab-content {
+    padding: 1rem 0rem;
+}
+
+.mdbook-tab-content table {
+    margin: unset;
+}
diff --git a/component-model/theme/tabs.js b/component-model/theme/tabs.js
new file mode 100644
index 00000000..8d335667
--- /dev/null
+++ b/component-model/theme/tabs.js
@@ -0,0 +1,75 @@
+/**
+ * Change active tab of tabs.
+ *
+ * @param {Element} container
+ * @param {string} name
+ */
+const changeTab = (container, name) => {
+    for (const child of container.children) {
+        if (!(child instanceof HTMLElement)) {
+            continue;
+        }
+
+        if (child.classList.contains('mdbook-tabs')) {
+            for (const tab of child.children) {
+                if (!(tab instanceof HTMLElement)) {
+                    continue;
+                }
+
+                if (tab.dataset.tabname === name) {
+                    tab.classList.add('active');
+                } else {
+                    tab.classList.remove('active');
+                }
+            }
+        } else if (child.classList.contains('mdbook-tab-content')) {
+            if (child.dataset.tabname === name) {
+                child.classList.remove('hidden');
+            } else {
+                child.classList.add('hidden');
+            }
+        }
+    }
+};
+
+document.addEventListener('DOMContentLoaded', () => {
+    const tabs = document.querySelectorAll('.mdbook-tab');
+    for (const tab of tabs) {
+        tab.addEventListener('click', () => {
+            if (!(tab instanceof HTMLElement)) {
+                return;
+            }
+
+            if (!tab.parentElement || !tab.parentElement.parentElement) {
+                return;
+            }
+
+            const container = tab.parentElement.parentElement;
+            const name = tab.dataset.tabname;
+            const global = container.dataset.tabglobal;
+
+            changeTab(container, name);
+
+            if (global) {
+                localStorage.setItem(`mdbook-tabs-${global}`, name);
+
+                const globalContainers = document.querySelectorAll(
+                    `.mdbook-tabs-container[data-tabglobal="${global}"]`
+                );
+                for (const globalContainer of globalContainers) {
+                    changeTab(globalContainer, name);
+                }
+            }
+        });
+    }
+
+    const containers = document.querySelectorAll('.mdbook-tabs-container[data-tabglobal]');
+    for (const container of containers) {
+        const global = container.dataset.tabglobal;
+
+        const name = localStorage.getItem(`mdbook-tabs-${global}`);
+        if (name && document.querySelector(`.mdbook-tab[data-tabname="${name}"]`)) {
+            changeTab(container, name);
+        }
+    }
+});
diff --git a/component-model/theme/version-notice.css b/component-model/theme/version-notice.css
new file mode 100644
index 00000000..5ae986dd
--- /dev/null
+++ b/component-model/theme/version-notice.css
@@ -0,0 +1,37 @@
+.version-notice {
+    display: flex;
+    align-items: flex-start;
+    gap: 0.75rem;
+    padding: 0.75rem 1rem 0.75rem 1.25rem;
+    margin: 0 0 1.5rem 0;
+    background-color: var(--quote-bg);
+    border-left: 4px solid var(--sidebar-active, var(--fg));
+    border-radius: 0 4px 4px 0;
+    font-size: 0.95em;
+    line-height: 1.5;
+}
+
+.version-notice::before {
+    content: "";
+    flex-shrink: 0;
+    width: 1.15em;
+    height: 1.15em;
+    margin-top: 0.15em;
+    background-color: var(--sidebar-active, var(--fg));
+    -webkit-mask-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'><line x1='6' y1='3' x2='6' y2='15'/><circle cx='18' cy='6' r='3'/><circle cx='6' cy='18' r='3'/><path d='M18 9a9 9 0 0 1-9 9'/></svg>");
+    mask-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'><line x1='6' y1='3' x2='6' y2='15'/><circle cx='18' cy='6' r='3'/><circle cx='6' cy='18' r='3'/><path d='M18 9a9 9 0 0 1-9 9'/></svg>");
+    -webkit-mask-size: contain;
+    mask-size: contain;
+    -webkit-mask-repeat: no-repeat;
+    mask-repeat: no-repeat;
+    -webkit-mask-position: center;
+    mask-position: center;
+}
+
+.version-notice > *:first-child {
+    margin-top: 0;
+}
+
+.version-notice > *:last-child {
+    margin-bottom: 0;
+}