diff --git a/src/misc/wasm/Makefile b/src/misc/wasm/Makefile
--- a/src/misc/wasm/Makefile
+++ b/src/misc/wasm/Makefile
@@ -37,10 +37,36 @@
 OUT      := out-femtolisp
 endif

+# Keep the embedded distribution separate so packaging can never delete
+# the full distribution's packs when switching profiles.
+ifeq ($(TESSERA_WEB),1)
+OUT      := $(OUT)-tessera
+WEB_EMBEDDED := true
+WEB_EXTRAS :=
+WEB_PLUGIN_PACKS :=
+else
+WEB_EMBEDDED := false
+WEB_EXTRAS := workers.js wallet.js
+WEB_PLUGIN_PACKS := tikzjax asymptote
+endif
+
 SOURCES  := $(shell cat $(W)/sources.txt)
 # the Scheme interpreter: S7 (the default) or femtolisp (SCHEME=femtolisp,
 # src/Scheme/Femtolisp, docs/femtolisp), whose objects go to obj-femtolisp
 ifeq ($(SCHEME),femtolisp)
+# Keep the embedded distribution separate so packaging can never delete
+# the full distribution's packs when switching profiles.
+ifeq ($(TESSERA_WEB),1)
+OUT      := $(OUT)-tessera
+WEB_EMBEDDED := true
+WEB_EXTRAS :=
+WEB_PLUGIN_PACKS :=
+else
+WEB_EMBEDDED := false
+WEB_EXTRAS := workers.js wallet.js
+WEB_PLUGIN_PACKS := tikzjax asymptote
+endif
+
 SOURCES  := $(filter-out Scheme/S7/%,$(SOURCES)) \
   Scheme/Femtolisp/fl_core.c Scheme/Femtolisp/fl_llt.c \
   Scheme/Femtolisp/femtolisp_tm.cpp
@@ -131,6 +157,13 @@

 web: $(OUT)/web/texmacs.html $(OUT)/web/texmacs-files.json $(WEB_ICONS) $(OUT)/web/index.html $(OUT)/web/downloads.html $(OUT)/web/features.html $(SCREENSHOTS) $(OUT)/web/changes.html $(OUT)/web/changes.md $(OUT)/web/thanks.html $(OUT)/web/thanks.md $(OUT)/web/fixes.html $(OUT)/web/texmacs-64.png licenses tikzjax asymptote python r

+# Browser editor assets only. The full web target also builds the public site,
+# documentation screenshots and external computational runtimes.
+tessera-web:
+	$(MAKE) -f $(W)/Makefile TESSERA_WEB=1 tessera-assets
+
+tessera-assets: $(OUT)/web/texmacs-files.json $(WEB_ICONS) licenses
+
 # the licenses of the components (TeXmacs/misc/licenses, also in the
 # packages of the page), as files of the site: out/web/licenses/
 licenses: $(OUT)/web/licenses/README.md
@@ -278,11 +311,12 @@
 	@mkdir -p $(OUT)/web/screenshots
 	cp $< $@

-$(OUT)/web/texmacs.html: $(OBJECTS) $(LIBDEPS) $(W)/progress.js $(W)/packages.js $(W)/web-pre.js $(W)/files.js $(W)/frame.js $(W)/clipboard.js $(W)/print.js $(W)/workers.js $(W)/javascript.js $(W)/ime.js $(W)/wallet.js $(W)/shell.html
+$(OUT)/web/texmacs.html: $(OBJECTS) $(LIBDEPS) $(W)/progress.js $(W)/packages.js $(W)/web-pre.js $(W)/files.js $(W)/frame.js $(W)/clipboard.js $(W)/print.js $(W)/workers.js $(W)/javascript.js $(W)/ime.js $(addprefix $(W)/,$(WEB_EXTRAS)) $(W)/shell.html
 	@mkdir -p $(OUT)/web
 	em++ $(LDFLAGS) -lidbfs.js --pre-js $(W)/progress.js --pre-js $(W)/packages.js --pre-js $(W)/web-pre.js \
-	  --pre-js $(W)/files.js --pre-js $(W)/frame.js --pre-js $(W)/clipboard.js --pre-js $(W)/print.js --pre-js $(W)/workers.js --pre-js $(W)/javascript.js --pre-js $(W)/ime.js --pre-js $(W)/wallet.js --shell-file $(W)/shell.html \
+	  --pre-js $(W)/files.js --pre-js $(W)/frame.js --pre-js $(W)/clipboard.js --pre-js $(W)/print.js --pre-js $(W)/javascript.js --pre-js $(W)/ime.js $(foreach f,$(WEB_EXTRAS),--pre-js $(W)/$(f)) --shell-file $(W)/shell.html \
 	  $(OBJECTS) $(LIBS) -o $@
+	perl -pi -e "s/\@TM_EMBEDDED\@/$(WEB_EMBEDDED)/" $@
 	perl -pi -e "s/\@TM_WASM_SIZE\@/$$(wc -c < $(OUT)/web/texmacs.wasm | tr -d ' ')/" $@
 	perl -pi -e "s/\@TM_VERSION\@/$$(sed -n 's/^#define TEXMACS_VERSION \"\(.*\)\"/\1/p' $(W)/tm_configure.hpp)/" $@
 	-command -v brotli > /dev/null && brotli -f -q 9 -k $(OUT)/web/texmacs.wasm $(OUT)/web/texmacs.js
@@ -313,12 +347,12 @@
 # (misc/wasm/build-info.py: the commit, the versions, the sizes), written
 # once the program and the files are there, then packaged again
 BUILD_INFO := $(TM)/TeXmacs/doc/about/welcome/texmacs-vue-build.en.tm
-$(OUT)/web/texmacs-files.json: FORCE plugins-sync $(OUT)/web/texmacs.html tikzjax asymptote $(PACKAGE_DEPS)
-	@mkdir -p $(OUT)/web
-	python3 $(W)/package.py $(TM)/TeXmacs $(OUT)/web $(W)/boot-files.txt $(PACKAGE_EXTRA)
+$(OUT)/web/texmacs-files.json: FORCE plugins-sync $(OUT)/web/texmacs.html $(WEB_PLUGIN_PACKS) $(PACKAGE_DEPS)
+	@mkdir -p $(OUT)/web
+	TESSERA_WEB=$(TESSERA_WEB) python3 $(W)/package.py $(TM)/TeXmacs $(OUT)/web $(W)/boot-files.txt $(PACKAGE_EXTRA)
 	$(BROTLI_PACKS)
-	python3 $(W)/build-info.py $(TM) $(CURDIR) $(MUPDF) "$(THORVG)" $(BUILD_INFO)
-	python3 $(W)/package.py $(TM)/TeXmacs $(OUT)/web $(W)/boot-files.txt $(PACKAGE_EXTRA)
+	python3 $(W)/build-info.py $(TM) $(CURDIR) $(MUPDF) "$(THORVG)" $(BUILD_INFO) $(OUT)/web
+	TESSERA_WEB=$(TESSERA_WEB) python3 $(W)/package.py $(TM)/TeXmacs $(OUT)/web $(W)/boot-files.txt $(PACKAGE_EXTRA)
 	$(BROTLI_PACKS)

 BROTLI_PACKS = -command -v brotli > /dev/null && for f in $(OUT)/web/tm-*.pack $(OUT)/web/tm-font-*; do \
@@ -422,4 +456,4 @@
 clean:
 	rm -rf $(OBJ) $(OUT)

-.PHONY: all web node clean licenses tikzjax asymptote python r plugins-sync femtolisp-cache
+.PHONY: all web tessera-web tessera-assets node clean licenses tikzjax asymptote python r plugins-sync femtolisp-cache
diff --git a/src/misc/wasm/package.py b/src/misc/wasm/package.py
--- a/src/misc/wasm/package.py
+++ b/src/misc/wasm/package.py
@@ -78,7 +78,19 @@
   return (any (rel.startswith (d) for d in LAZY_DIRS) and
           os.path.splitext (rel)[1].lower () in LAZY_EXTS)

+# Tessera handles document storage and has no execution-session UI. Keep
+# conversion plug-ins, styles, fonts and the native editing resources.
+EMBEDDED = os.environ.get ('TESSERA_WEB') == '1'
+EMBEDDED_EXCLUDE = ['plugins/' + p for p in ('ai', 'python', 'r', 'tikz', 'asymptote')]
+EMBEDDED_EXCLUDE += ['misc/font-samples']
+# The core's lazy format registry loads this even for regular manuscripts.
+EMBEDDED_KEEP = ['plugins/python/progs/python-format.scm']
+
 def excluded (rel):
+  if EMBEDDED and any (p == rel or p.startswith (rel + '/') for p in EMBEDDED_KEEP):
+    return False
+  if EMBEDDED and any (rel == d or rel.startswith (d + '/') for d in EMBEDDED_EXCLUDE):
+    return True
   if any (rel == d or rel.startswith (d + '/') for d in PLUGIN_DOCS): return False
   return any (fnmatch.fnmatch (rel, e) or rel.startswith (e + '/') for e in EXCLUDE)

diff --git a/src/misc/wasm/shell.html b/src/misc/wasm/shell.html
--- a/src/misc/wasm/shell.html
+++ b/src/misc/wasm/shell.html
@@ -4,6 +4,7 @@
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>TeXmacs Upsilon</title>
+<meta name="tessera-embedded" content="@TM_EMBEDDED@">
 <!-- the logo of TeXmacs Upsilon (TeXmacs/misc/images, made by
      misc/icons/vue-logo/make-vue-logo.py, copied by misc/wasm/Makefile); Safari
      takes the .ico -->
@@ -21,6 +22,8 @@
   canvas { position: absolute; left: 0; top: 0; width: 100%; height: 100%;
            display: block; outline: none; }
   /* until the panel of misc/wasm/progress.js replaces it */
+  .tessera-embedded #tm-frame, .tessera-embedded #tm-loading,
+  .tessera-embedded #status { display: none !important; }
   #status { position: fixed; left: 0; right: 0; top: 40%; text-align: center;
             font: 16px -apple-system, "Helvetica Neue", sans-serif; color: #222; }
 </style>
@@ -31,7 +34,10 @@
 <div id="status">Loading TeXmacs Upsilon…</div>
 <script>
   var statusElement = document.getElementById('status');
+  var embedded = document.querySelector('meta[name="tessera-embedded"]').content === 'true';
+  if (embedded) document.documentElement.classList.add('tessera-embedded');
   var Module = {
+    tmEmbedded: embedded,
     canvas: document.getElementById('canvas'),
     // the size of texmacs.wasm, written by the build (misc/wasm/Makefile)
     // for the progress of its download (misc/wasm/progress.js)
diff --git a/src/misc/wasm/web-pre.js b/src/misc/wasm/web-pre.js
--- a/src/misc/wasm/web-pre.js
+++ b/src/misc/wasm/web-pre.js
@@ -166,6 +166,12 @@
     var m = /^(TEXMACS_[A-Z0-9_]+):(.*)$/.exec (e);
     if (m) ENV[m[1]] = m[2];
   });
+  // The host application persists manuscripts. Give each embedded editor
+  // its own transient preferences and skip the standalone home lock.
+  if (Module['tmEmbedded']) {
+    FS.mkdirTree ('/home/web/.TeXmacs');
+    return;
+  }
   FS.mkdirTree ('/home/web');
   FS.mount (IDBFS, { autoPersist: false }, '/home/web');
   addRunDependency ('home');
@@ -513,7 +519,7 @@
     });
   }

-  if (typeof window !== 'undefined') {
+  if (typeof window !== 'undefined' && !Module['tmEmbedded']) {
     window.addEventListener ('pagehide', function () { flush (); });
     document.addEventListener ('visibilitychange', function () {
       if (document.visibilityState === 'hidden') flush ();
diff --git a/src/misc/wasm/frame.js b/src/misc/wasm/frame.js
--- a/src/misc/wasm/frame.js
+++ b/src/misc/wasm/frame.js
@@ -349,6 +349,7 @@
   var TABS = 'texmacs-tabs', tabsTop = false;
   try { tabsTop = localStorage.getItem (TABS) === 'top'; } catch (e) {}
   function setTabsPosition (pos) {
+    if (Module['tmEmbedded']) return;
     var top = (pos === 'top');
     try { localStorage.setItem (TABS, top ? 'top' : 'left'); } catch (e) {}
     if (top === tabsTop && bar) return;
@@ -604,9 +605,15 @@
     window.addEventListener ('pointerup', up);
     window.addEventListener ('pointercancel', up);
   }
+  var styleInstalled = false;
+  function installStyle () {
+    if (styleInstalled) return;
+    var st = el ('style'); st.textContent = style; document.head.appendChild (st);
+    styleInstalled = true;
+  }
   function build () {
-    if (bar || typeof document === 'undefined') return;
-    var st = el ('style'); st.textContent = style; document.head.appendChild (st);
+    if (bar || typeof document === 'undefined' || Module['tmEmbedded']) return;
+    installStyle ();
     // dark as the system until TeXmacs sets its theme (set_vue_theme)
     try {
       if (!document.documentElement.classList.contains ('tm-theme-set') && window.matchMedia &&
@@ -1166,6 +1173,7 @@
   // fill (box, close) makes its contents, closed (true when a button of
   // them closed it) is called once it is closed
   function dialog (title, fill, closed) {
+    installStyle ();
     var old = document.getElementById ('tm-about');
     if (old) old.remove ();
     var back = el ('div'); back.id = 'tm-about';
@@ -1358,7 +1366,7 @@
     placeMenu ();
   }

-  if (typeof document !== 'undefined') {
+  if (typeof document !== 'undefined' && !Module['tmEmbedded']) {
     if (document.readyState === 'loading') document.addEventListener ('DOMContentLoaded', build);
     else build ();
   }
@@ -1421,7 +1429,7 @@
       return tabs.some (function (t) { return t.modified; });
     }
   }
-  if (typeof window !== 'undefined')
+  if (typeof window !== 'undefined' && !Module['tmEmbedded'])
     window.addEventListener ('beforeunload', function (e) {
       if (leaving || !unsaved ()) return;
       e.preventDefault ();
diff --git a/src/misc/wasm/files.js b/src/misc/wasm/files.js
--- a/src/misc/wasm/files.js
+++ b/src/misc/wasm/files.js
@@ -402,7 +402,7 @@
              : 'The files kept in this browser have no backup yet.',
            { ms: 12000, id: 'tm-backup-reminder', button: ['Back up', function () { backup (); }] });
   }
-  if (typeof window !== 'undefined' && typeof tmProgress !== 'undefined')
+  if (typeof window !== 'undefined' && typeof tmProgress !== 'undefined' && !Module['tmEmbedded'])
     tmProgress.running (function () { setTimeout (remind, 8000); });

   // the bytes of a backup -> { note, entries: [{ rel (in the home), bytes }] };
@@ -949,7 +949,7 @@
       }).catch (function (err) { console.error ('TeXmacs: the drop failed', err); });
     }, true);
   }
-  if (typeof window !== 'undefined') installDrop ();
+  if (typeof window !== 'undefined' && !Module['tmEmbedded']) installDrop ();

   /****************************************************************************
   * A document from the web: texmacs.html?open=<url>
@@ -1029,7 +1029,7 @@
       });
   }

-  if (typeof location !== 'undefined') {
+  if (typeof location !== 'undefined' && !Module['tmEmbedded']) {
     var address = new URLSearchParams (location.search);
     var opened = address.get ('open') ? openFromWeb (address.get ('open')) : Promise.resolve ();
     if (address.get ('file')) {
diff --git a/src/misc/wasm/build-info.py b/src/misc/wasm/build-info.py
--- a/src/misc/wasm/build-info.py
+++ b/src/misc/wasm/build-info.py
@@ -14,7 +14,7 @@
 import hashlib, json, os, re, shutil, subprocess, sys, time

 src, build, mupdf, thorvg, out = sys.argv[1:6]
-web = os.path.join (build, 'out', 'web')
+web = os.path.join (build, sys.argv[6] if len (sys.argv) > 6 else 'out/web')

 def read (p):
   try: