diff --git a/build/Site.hs b/build/Site.hs
index 0b42e04..b5e5447 100644
--- a/build/Site.hs
+++ b/build/Site.hs
@@ -404,7 +404,9 @@ rules = do
                     let ts = fromMaybe [] (lookupStringList "tags" meta)
                     return $ any (\t -> t == p || (p ++ "/") `isPrefixOf` t) ts
 
-                portalList name p = listField name essayCtx $ do
+                itemCtx = dateField "date-iso" "%Y-%m-%d" <> essayCtx
+
+                portalList name p = listField name itemCtx $ do
                     essays  <- loadAll (allEssays              .&&. hasNoVersion)
                     posts   <- loadAll ("content/blog/*.md"    .&&. hasNoVersion)
                     fiction <- loadAll ("content/fiction/*.md" .&&. hasNoVersion)
diff --git a/static/css/library.css b/static/css/library.css
index 07f84e9..7bd8471 100644
--- a/static/css/library.css
+++ b/static/css/library.css
@@ -5,9 +5,54 @@
     font-size: var(--text-size-small);
     color: var(--text-muted);
     margin-top: 0.25rem;
+    margin-bottom: 1.25rem;
+}
+
+/* ============================================================
+   SORT CONTROLS
+   ============================================================ */
+
+.library-controls {
+    display: flex;
+    align-items: center;
+    gap: 0.6rem;
     margin-bottom: 2.5rem;
 }
 
+.library-controls-label {
+    font-family: var(--font-sans);
+    font-size: 0.75rem;
+    color: var(--text-faint);
+}
+
+.library-controls-options {
+    display: flex;
+    gap: 0.3rem;
+}
+
+.library-sort-btn {
+    font-family: var(--font-sans);
+    font-size: 0.75rem;
+    color: var(--text-muted);
+    background: none;
+    border: 1px solid var(--border);
+    border-radius: 2px;
+    padding: 0.15em 0.55em;
+    cursor: pointer;
+    transition: border-color 0.1s, color 0.1s;
+}
+
+.library-sort-btn:hover {
+    border-color: var(--border-muted);
+    color: var(--text);
+}
+
+.library-sort-btn.is-active {
+    border-color: var(--text-muted);
+    color: var(--text);
+    font-weight: 600;
+}
+
 /* ============================================================
    PORTAL SECTIONS
    ============================================================ */
diff --git a/templates/library.html b/templates/library.html
index cf13538..e9d9435 100644
--- a/templates/library.html
+++ b/templates/library.html
@@ -2,11 +2,20 @@
 <h1 class="page-title">Library</h1>
 <p class="library-intro">Everything on this site, organized by portal.</p>
 
+<div class="library-controls">
+    <span class="library-controls-label">Sort by</span>
+    <div class="library-controls-options" role="group" aria-label="Sort order">
+        <button class="library-sort-btn" data-sort="date">date</button>
+        <button class="library-sort-btn" data-sort="title">title</button>
+        <button class="library-sort-btn" data-sort="score">epistemic effort</button>
+    </div>
+</div>
+
 $if(research-entries)$
 <section class="library-section">
 <h2 id="research"><a href="/research/">Research</a></h2>
 <ul class="library-list">$for(research-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -20,7 +29,7 @@ $if(nonfiction-entries)$
 <section class="library-section">
 <h2 id="nonfiction"><a href="/nonfiction/">Nonfiction</a></h2>
 <ul class="library-list">$for(nonfiction-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -34,7 +43,7 @@ $if(fiction-entries)$
 <section class="library-section">
 <h2 id="fiction"><a href="/fiction/">Fiction</a></h2>
 <ul class="library-list">$for(fiction-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -48,7 +57,7 @@ $if(poetry-entries)$
 <section class="library-section">
 <h2 id="poetry"><a href="/poetry/">Poetry</a></h2>
 <ul class="library-list">$for(poetry-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -62,7 +71,7 @@ $if(music-entries)$
 <section class="library-section">
 <h2 id="music"><a href="/music/">Music</a></h2>
 <ul class="library-list">$for(music-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -76,7 +85,7 @@ $if(ai-entries)$
 <section class="library-section">
 <h2 id="ai"><a href="/ai/">AI</a></h2>
 <ul class="library-list">$for(ai-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -90,7 +99,7 @@ $if(tech-entries)$
 <section class="library-section">
 <h2 id="tech"><a href="/tech/">Tech</a></h2>
 <ul class="library-list">$for(tech-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -104,7 +113,7 @@ $if(miscellany-entries)$
 <section class="library-section">
 <h2 id="miscellany"><a href="/miscellany/">Miscellany</a></h2>
 <ul class="library-list">$for(miscellany-entries)$
-<li class="library-entry">
+<li class="library-entry" data-date="$date-iso$"$if(overall-score)$ data-score="$overall-score$"$endif$>
   <div class="library-entry-header">
     <a class="library-entry-title" href="$url$">$title$</a>
     <span class="library-entry-date">$date-created$</span>
@@ -115,3 +124,62 @@ $if(miscellany-entries)$
 $endif$
 
 </div>
+<script>
+(function () {
+    var STORAGE_KEY = 'library-sort';
+    var DEFAULT     = 'date';
+    var MODES       = { date: 1, title: 1, score: 1 };
+
+    function titleOf(entry) {
+        var el = entry.querySelector('.library-entry-title');
+        return el ? el.textContent.trim().toLowerCase() : '';
+    }
+
+    function compare(a, b, mode) {
+        if (mode === 'title') {
+            return titleOf(a).localeCompare(titleOf(b));
+        }
+        if (mode === 'score') {
+            // Entries without a score sink to the bottom; ties broken by date desc.
+            var hasA = a.dataset.score !== undefined;
+            var hasB = b.dataset.score !== undefined;
+            if (hasA && !hasB) return -1;
+            if (!hasA && hasB) return  1;
+            if (hasA && hasB) {
+                var diff = Number(b.dataset.score) - Number(a.dataset.score);
+                if (diff !== 0) return diff;
+            }
+            // fall through to date-desc tiebreak
+        }
+        // date desc (ISO strings sort lexicographically)
+        var da = a.dataset.date || '';
+        var db = b.dataset.date || '';
+        if (da < db) return  1;
+        if (da > db) return -1;
+        return 0;
+    }
+
+    function applySort(mode) {
+        if (!MODES[mode]) mode = DEFAULT;
+        document.querySelectorAll('.library-list').forEach(function (list) {
+            var entries = Array.prototype.slice.call(list.querySelectorAll('.library-entry'));
+            entries.sort(function (a, b) { return compare(a, b, mode); });
+            entries.forEach(function (el) { list.appendChild(el); });
+        });
+        document.querySelectorAll('.library-sort-btn').forEach(function (btn) {
+            btn.classList.toggle('is-active', btn.dataset.sort === mode);
+        });
+        try { localStorage.setItem(STORAGE_KEY, mode); } catch (e) {}
+    }
+
+    document.addEventListener('DOMContentLoaded', function () {
+        var saved;
+        try { saved = localStorage.getItem(STORAGE_KEY); } catch (e) {}
+        applySort(saved || DEFAULT);
+
+        document.querySelectorAll('.library-sort-btn').forEach(function (btn) {
+            btn.addEventListener('click', function () { applySort(btn.dataset.sort); });
+        });
+    });
+}());
+</script>