diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..908d5d3
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,69 @@
+This repository holds the source for sheets.ch and the writing published there.
+The two are licensed separately:
+
+  * Site source (everything outside src/content): MIT License
+  * Writing in src/content: Creative Commons Attribution 4.0 International
+  * Code samples inside that writing: MIT No Attribution (MIT-0)
+
+Product names and trademarks mentioned in the content belong to their owners.
+
+
+MIT License
+===========
+
+Copyright (c) 2026 Chad Sheets
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+
+Creative Commons Attribution 4.0 International (CC BY 4.0)
+==========================================================
+
+Copyright (c) 2016-2026 Chad Sheets
+
+The prose, images, and other non-code content under src/content may be shared
+and adapted for any purpose, including commercially, provided you give
+appropriate credit, link to the license, and indicate if changes were made.
+
+Summary:    https://creativecommons.org/licenses/by/4.0/
+Legal code: https://creativecommons.org/licenses/by/4.0/legalcode
+
+
+MIT No Attribution (MIT-0)
+==========================
+
+Copyright (c) 2016-2026 Chad Sheets
+
+Applies to code samples, commands, and configuration snippets that appear
+inside the content under src/content.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/package.json b/package.json
index e7bda6b..a0beb8c 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,7 @@
   },
   "keywords": [],
   "author": "",
-  "license": "ISC",
+  "license": "MIT",
   "description": "",
   "dependencies": {
     "@astrojs/mdx": "^4.3.13",
diff --git a/src/components/Footer.astro b/src/components/Footer.astro
index a7ea9e4..26646bd 100644
--- a/src/components/Footer.astro
+++ b/src/components/Footer.astro
@@ -1,6 +1,7 @@
 <footer class="site-footer container">
   <span>Built with Astro.</span>
   <a href="https://github.com/cjsheets/sheets.ch">Source on GitHub.</a>
+  <a href="/about-this-site">About this site.</a>
 </footer>
 
 <style>
diff --git a/src/components/Header.astro b/src/components/Header.astro
index faa5542..f61f8b9 100644
--- a/src/components/Header.astro
+++ b/src/components/Header.astro
@@ -13,7 +13,9 @@ const navLinks = [
 ];
 const currentPath = Astro.url.pathname;
 const isActive = (href: string) =>
-  href === '/' ? currentPath === '/' : currentPath.startsWith(href);
+  href === '/'
+    ? currentPath === '/' || currentPath.startsWith('/about')
+    : currentPath.startsWith(href);
 ---
 
 <header
diff --git a/src/pages/about-this-site.astro b/src/pages/about-this-site.astro
new file mode 100644
index 0000000..23fe9ae
--- /dev/null
+++ b/src/pages/about-this-site.astro
@@ -0,0 +1,111 @@
+---
+import BaseLayout from '../layouts/BaseLayout.astro';
+
+const repo = 'https://github.com/cjsheets/sheets.ch';
+const updated = new Date('2026-09-02');
+const updatedIso = updated.toISOString();
+const updatedLabel = updated.toLocaleDateString('en-US', {
+  year: 'numeric',
+  month: 'long',
+  day: 'numeric',
+  timeZone: 'UTC',
+});
+---
+
+<BaseLayout
+  title="About this site"
+  headerTitle="About this site"
+  description="What runs sheets.ch, what it collects about visitors (nothing), and how the writing and code can be reused."
+>
+  <div class="container">
+    <header class="page-header">
+      <h1 data-header-title>About this site</h1>
+      <p class="page-subtitle">
+        What runs here, what it collects, and what you can do with it.
+      </p>
+    </header>
+
+    <div class="site-notes">
+      <section aria-labelledby="tracking-heading">
+        <h2 id="tracking-heading">Tracking</h2>
+        <p>
+          This site is static HTML built with Astro and served by Cloudflare.
+          There are no analytics, cookies, forms, or third-party scripts. I
+          don't know who you are and I'm not trying to find out.
+        </p>
+        <p>
+          Cloudflare sees the request logs it needs to serve the pages (IP
+          address, user agent, that kind of thing). What it keeps is covered by
+          <a href="https://www.cloudflare.com/privacypolicy/"
+            >Cloudflare's privacy policy</a
+          >. If I add analytics later, I'll say so here.
+        </p>
+      </section>
+
+      <section aria-labelledby="reuse-heading">
+        <h2 id="reuse-heading">Reuse</h2>
+        <p>
+          The writing is licensed
+          <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a>.
+          Copy, quote, or translate it and link back here.
+        </p>
+        <p>
+          Code samples in the notes are licensed
+          <a href="https://opensource.org/license/mit-0">MIT-0</a>, so paste
+          them wherever you like without an attribution line. The site's own
+          source is MIT and lives <a href={repo}>on GitHub</a>.
+        </p>
+      </section>
+
+      <section aria-labelledby="caveats-heading">
+        <h2 id="caveats-heading">Caveats</h2>
+        <p>
+          Most notes here are things I fixed once, written down so I can fix
+          them again. They worked on my machine on the day I wrote them.
+          Versions drift and defaults change, so test anything before running it
+          somewhere that matters. Everything is provided as-is, without
+          warranty.
+        </p>
+        <p>
+          Product names belong to their owners. Opinions are mine, not my
+          employer's.
+        </p>
+      </section>
+
+      <section aria-labelledby="contact-heading">
+        <h2 id="contact-heading">Contact</h2>
+        <p>
+          Found an error, or something of yours used without credit?
+          <a href={`${repo}/issues`}>Open an issue</a> on the source repo.
+        </p>
+      </section>
+
+      <p class="meta">
+        Last updated <time datetime={updatedIso}>{updatedLabel}</time>.
+      </p>
+    </div>
+  </div>
+</BaseLayout>
+
+<style>
+  .site-notes {
+    max-width: 36rem;
+  }
+  .site-notes section + section {
+    margin-top: 2rem;
+  }
+  .site-notes h2 {
+    margin-top: 0;
+  }
+  .site-notes p {
+    margin: 0 0 1rem;
+  }
+  .site-notes p:last-child {
+    margin-bottom: 0;
+  }
+  .site-notes .meta {
+    margin-top: 2.4rem;
+    color: var(--color-text-muted);
+    font-size: 0.72rem;
+  }
+</style>