diff --git a/.gitignore b/.gitignore
index bc9f1d3..9718006 100644
--- a/.gitignore
+++ b/.gitignore
@@ -69,6 +69,8 @@ pub/globster/ctl.html
 pub/globster/daemon.html
 pub/globster/feed.atom
 pub/globster/launch.html
+pub/guestbook.html
+pub/guestbook/thanks.html
 pub/index.html
 pub/ncdc.html
 pub/ncdc/changes.html
diff --git a/Makefile b/Makefile
index 22e9253..60e7140 100644
--- a/Makefile
+++ b/Makefile
@@ -31,6 +31,8 @@ PAGES=\
 	"dump/grenamr.md"\
 	"dump/insbench.md"\
 	"dump/nccolour.md"\
+	"guestbook.md"\
+	"guestbook/thanks.md"\
 	"globster.md"\
 	"globster/api.pod           https://g.blicky.net/globster.git/plain/doc/api.pod             The Globster D-Bus API"\
 	"globster/ctl.pod           https://g.blicky.net/globster.git/plain/doc/globsterctl.pod     The globsterctl(1) Man Page"\
diff --git a/dat/guestbook.md b/dat/guestbook.md
new file mode 100644
index 0000000..8402cf6
--- /dev/null
+++ b/dat/guestbook.md
@@ -0,0 +1,20 @@
+% Guestbook
+
+It's 2022 and I figured this little site could use a guestbook. Want to leave a
+message? Fill out the form below. Messages are added manually, so it may take a
+day or two for yours to show up. Markdown is supported.
+
+This guestbook exists just for sillyness; if you have a question or want to
+report feedback for a particular project, better open an issue at the
+respective issue tracker or send a mail to
+[projects@yorhel.nl](mailto:projects@yorhel.nl) instead.
+
+<form method="POST" action="/cgi-bin/guestbook.cgi">
+<input type="text" name="name" placeholder="Your name (optional)">
+<textarea name="message" placeholder="Message" required cols=50 rows=5></textarea>
+<input type="submit" value="Submit">
+</form>
+
+# Entries
+
+The guestbook is empty, be the first to post!
diff --git a/dat/guestbook/thanks.md b/dat/guestbook/thanks.md
new file mode 100644
index 0000000..c78a650
--- /dev/null
+++ b/dat/guestbook/thanks.md
@@ -0,0 +1,3 @@
+% Message submitted!
+
+Thanks for posting to my guestbook! It may take a day or two for your message to show up.
diff --git a/dat/ncdu.md b/dat/ncdu.md
index b2733cd..c170619 100644
--- a/dat/ncdu.md
+++ b/dat/ncdu.md
@@ -13,15 +13,16 @@ Zig version (stable)
 
     See the [beta release announcement](/doc/ncdu2) for information about the
     motivation for the rewrite and some of the differences with the C version.
-    Contrary to popular belief, version 2.x does **not** yet implement parallel
-    scanning, so don't expect any order-of-magnitude performance
-    improvements... yet.
 
     Note that the [Zig language](https://ziglang.org/) and compiler are still
     very much unstable. This version of ncdu will *only* work with the version
     of the Zig compiler noted above. Use the ncdu 1.x branch if this does not
     work for you or if you need a more stable compilation environment.
 
+    **Linux users/distros** may want to apply [this patch to
+    Zig](https://github.com/ziglang/zig/pull/11295) to fix a [possible
+    crash](https://code.blicky.net/yorhel/ncdu/issues/192).
+
     Convenient static binaries for Linux:
     [i486](/download/ncdu-2.1.1-linux-i386.tar.gz),
     [x86_64](/download/ncdu-2.1.1-linux-x86_64.tar.gz),
diff --git a/pub/cgi-bin/guestbook.cgi b/pub/cgi-bin/guestbook.cgi
new file mode 100755
index 0000000..6701f63
--- /dev/null
+++ b/pub/cgi-bin/guestbook.cgi
@@ -0,0 +1,32 @@
+#!/usr/bin/perl
+
+use v5.26;
+use CGI::Minimal;
+
+die if !$ENV{CONTENT_LENGTH};
+CGI::Minimal::max_read_size(128*1024);
+my $cgi = CGI::Minimal->new;
+die if $cgi->truncated;
+
+open my $S, '|-', qw'/usr/sbin/sendmail -t -f dev@yorhel.nl' or die $!;
+printf $S <<'_', $cgi->param('name'), $cgi->param('message');
+To: dev@yorhel.nl
+From: dev@yorhel.nl
+Subject: Guestbook post
+Content-Type: text/plain; charset='UTF-8'
+
+Name: %s
+
+Message:
+
+%s
+_
+close $S or die;
+
+print <<'_';
+Status: 303
+Content-Type: text/plain
+Location: https://dev.yorhel.nl/guestbook/thanks
+
+Redirecting...
+_
diff --git a/pub/style.css b/pub/style.css
index 4bb14f4..634734c 100644
--- a/pub/style.css
+++ b/pub/style.css
@@ -54,7 +54,7 @@ main h3 { font-size: 120%; color: #000; margin: 1em 0 .3em 0; text-decoration: n
 main code { font-family: monospace }
 main pre { font-family: monospace; font-size: 80%; margin: 0 0 10px 18px; display: block; padding: 0 0 0 15px; border-left: 1px dotted #999; overflow-x: auto } 
 main pre * { font-size: inherit; font-family: inherit }
-main p, main figure, main ul, main ol, main dl, main pre, main figure, main table { margin-bottom: 0.7em; margin-left: 1em }
+main p, main figure, main ul, main ol, main dl, main pre, main figure, main table, main form { margin-bottom: 0.7em; margin-left: 1em }
 main ul ul { margin-bottom: 0.5em }
 main ul, main ol { margin-left: 2.5em }
 main li { margin-bottom: .1em }
@@ -66,6 +66,8 @@ main figcaption { display: none }
 main table th, main table td { font-size: 12.8px; padding: 1px 7px }
 main td em { font-style: normal; text-decoration: underline }
 main table th { font-weight: bold }
+main textarea { width: 95% }
+main input[type="submit"] { padding: 1px 5px }
 
 main section.footnotes hr { display: none }
 main section.footnotes { margin: 40px 10px 10px 10px }
diff --git a/template.html b/template.html
index dc78f5a..358765f 100644
--- a/template.html
+++ b/template.html
@@ -127,7 +127,8 @@
                     </ul>
                     $endif$
                     <ul>
-                        <li><a href="/contributing.html" class="small item1-contributing">Contributing</a></li>
+                        <li><a href="/contributing" class="small item1-contributing">Contributing</a></li>
+                        <li><a href="/guestbook" class="small item1-guestbook">Guestbook</a></li>
                     </ul>
                 </nav>