diff --git a/pretext/pretext.py b/pretext/pretext.py
index ed4c736e5..7ef27eb63 100755
--- a/pretext/pretext.py
+++ b/pretext/pretext.py
@@ -3428,6 +3428,12 @@ def _parse_runestone_services(et):
 
     return (rs_js, rs_css, rs_cdn_url, rs_version)
 
+# Update stringparams with Runestone Services information
+def _set_runestone_stringparams(stringparams, rs_js, rs_css, rs_version):
+    stringparams["rs-js"] = rs_js
+    stringparams["rs-css"] = rs_css
+    stringparams["rs-version"] = rs_version
+
 # A helper function to query the latest Runestone
 # Services file, while failing gracefully
 
@@ -3477,9 +3483,7 @@ def _runestone_services(stringparams):
         rs_version = "dev"
         services_xml = None
         # Return, plus side-effect
-        stringparams["rs-js"] = rs_js
-        stringparams["rs-css"] = rs_css
-        stringparams["rs-version"] = rs_version
+        _set_runestone_stringparams(stringparams, rs_js, rs_css, rs_version)
         return (rs_js, rs_css, rs_cdn_url, rs_version, services_xml)
 
     # Otherwise, we have a URL pointing to the Runestone server/CDN
@@ -3537,9 +3541,7 @@ def _runestone_services(stringparams):
     rs_js, rs_css, rs_cdn_url, rs_version = _parse_runestone_services(services)
 
     # Return, plus side-effect
-    stringparams["rs-js"] = rs_js
-    stringparams["rs-css"] = rs_css
-    stringparams["rs-version"] = rs_version
+    _set_runestone_stringparams(stringparams, rs_js, rs_css, rs_version)
     return (rs_js, rs_css, rs_cdn_url, rs_version, services_xml)
 
 
@@ -3784,9 +3786,26 @@ def html(xml, pub_file, stringparams, xmlid_root, file_format, extra_xsl, out_fi
     # names for scratch directories
     tmp_dir = get_temporary_directory()
 
+    add_runestone_services = True
+    # quick and dirty tries to use existing rs services
+    # on failure, will get new ones
+    if "html.quick-dirty" in stringparams:
+        try:
+            services_record_files = os.path.join(dest_dir, "_static", "_runestone-services.xml")
+            with open(services_record_files, 'r') as f:
+                services_xml = f.read()
+            services = ET.fromstring(services_xml)
+            rs_js, rs_css, rs_cdn_url, rs_version = _parse_runestone_services(services)
+            _set_runestone_stringparams(stringparams, rs_js, rs_css, rs_version)
+            log.info("Quick and dirty HTML is using old Runestone Services. Delete _static/_runestone-services.xml from output to update Runestone.")
+            add_runestone_services = False
+        except:
+            log.info("Quick and dirty HTML failed to use old Runestone Services. Will download Runestone.")
+
     # interrogate Runestone server (or debugging switches) and populate
     # NB: stringparams is augmented with Runestone Services information
-    _place_runestone_services(tmp_dir, stringparams)
+    if add_runestone_services:
+        _place_runestone_services(tmp_dir, stringparams)
 
     # support publisher file, and subtree argument
     if pub_file:
@@ -3799,15 +3818,16 @@ def html(xml, pub_file, stringparams, xmlid_root, file_format, extra_xsl, out_fi
     else:
         extraction_xslt = os.path.join(get_ptx_xsl_path(), "pretext-html.xsl")
 
-    # place managed directories - some of these (Asymptote HTML) are
-    # consulted during the XSL run and so need to be placed beforehand
-    copy_managed_directories(tmp_dir, external_abs=external_abs, generated_abs=generated_abs)
+    if "html.quick-dirty" not in stringparams:
+        # place managed directories - some of these (Asymptote HTML) are
+        # consulted during the XSL run and so need to be placed beforehand
+        copy_managed_directories(tmp_dir, external_abs=external_abs, generated_abs=generated_abs)
 
-    # place JS in scratch directory
-    copy_html_js(tmp_dir)
+        # place JS in scratch directory
+        copy_html_js(tmp_dir)
 
-    # build or copy theme
-    build_or_copy_theme(xml, pub_file, stringparams, tmp_dir)
+        # build or copy theme
+        build_or_copy_theme(xml, pub_file, stringparams, tmp_dir)
 
     # Write output into temporary directory
     log.info("converting {} to HTML in {}".format(xml, tmp_dir))
diff --git a/xsl/pretext-assembly.xsl b/xsl/pretext-assembly.xsl
index 57ddcf46a..4e908974d 100644
--- a/xsl/pretext-assembly.xsl
+++ b/xsl/pretext-assembly.xsl
@@ -260,6 +260,63 @@ along with PreTeXt.  If not, see <http://www.gnu.org/licenses/>.
     </xsl:copy>
 </xsl:template>
 
+
+<!-- Pruning templates generate a subtree towards $target-node -->
+<!-- that prunes as many other branches as possible while      -->
+<!-- retaining halfway decent output of the desire tree.       -->
+<xsl:template match="node()|@*" mode="pruning">
+    <xsl:param name="target-node"/>
+    <xsl:choose>
+        <!-- This node contains the target node, copy and keep going -->
+        <xsl:when test="count(descendant::*|$target-node) = count(descendant::*)">
+            <xsl:copy>
+                <xsl:apply-templates select="node()|@*" mode="pruning">
+                    <xsl:with-param name="target-node" select="$target-node"/>
+                </xsl:apply-templates>
+            </xsl:copy>
+        </xsl:when>
+        <!-- This node is target node, keep it all -->
+        <xsl:when test="count(.|$target-node) = 1">
+            <xsl:apply-templates select="." mode="pruning-keep"/>
+        </xsl:when>
+        <!-- Shift to aggressive pruning -->
+        <xsl:otherwise>
+            <xsl:apply-templates select="." mode="pruning-prune"/>
+        </xsl:otherwise>
+    </xsl:choose>
+</xsl:template>
+
+<!-- If we hit frontmatter or docinfo, preserve all the content   -->
+<!-- docinfo and bookinfo have important config info. frontmatter -->
+<!-- has authors/subtitle/etc...                                  -->
+<xsl:template match="frontmatter|docinfo|bookinfo" mode="pruning">
+    <xsl:copy>
+        <xsl:apply-templates select="node()|@*" mode="pruning-keep"/>
+    </xsl:copy>
+</xsl:template>
+
+<!-- Preserve anything from here on down -->
+<xsl:template match="node()|@*" mode="pruning-keep">
+    <xsl:copy>
+        <xsl:apply-templates select="node()|@*" mode="pruning-keep"/>
+    </xsl:copy>
+</xsl:template>
+
+<!-- Once aggressively pruning, only keep structural elements that give us -->
+<!-- numbering and toc info. We could prune these and lose that, but       -->
+<!-- keeping them is cheap and looks a lot less broken on generated pages. -->
+<xsl:template match="&STRUCTURAL;|@*" mode="pruning-prune">
+    <xsl:copy>
+        <xsl:apply-templates select="&STRUCTURAL;|title|@*" mode="pruning-prune">
+        </xsl:apply-templates>
+    </xsl:copy>
+</xsl:template>
+
+<!-- If we hit a title, grab all the contents so the ToC gets content-->
+<xsl:template match="title" mode="pruning-prune">
+    <xsl:apply-templates select="." mode="pruning-keep"/>
+</xsl:template>
+
 <!-- These templates initiate and create several iterations of -->
 <!-- the source tree via modal templates.  Think of each as a  -->
 <!-- "pass" through the source. Generally this constructs the  -->
@@ -288,15 +345,6 @@ along with PreTeXt.  If not, see <http://www.gnu.org/licenses/>.
 </xsl:variable>
 <xsl:variable name="version" select="exsl:node-set($version-rtf)"/>
 
-<xsl:variable name="commentary-rtf">
-    <xsl:apply-templates select="$version" mode="commentary"/>
-</xsl:variable>
-<xsl:variable name="commentaried" select="exsl:node-set($commentary-rtf)"/>
-
-<!-- A global list of all "webwork" used for       -->
-<!-- efficient backward-compatible indentification -->
-<xsl:variable name="all-webwork" select="$commentaried//webwork"/>
-
 <!-- Support for versions mean there may be multiple instances of  -->
 <!-- the same structure in authored source, and conceivably they   -->
 <!-- might all be absent once a version has been selected.  We are -->
@@ -307,6 +355,32 @@ along with PreTeXt.  If not, see <http://www.gnu.org/licenses/>.
 <xsl:variable name="version-docinfo" select="$version-root/docinfo"/>
 <xsl:variable name="version-document-root" select="$version-root/*[not(self::docinfo)]"/>
 
+<!-- see pretext-html for full version of these params             -->
+<xsl:param name="subtree" select="''"/>
+<xsl:param name="html.quick-dirty" select="''"/>
+<xsl:variable name="pruning-tree-rtf">
+    <xsl:choose>
+        <xsl:when test="$subtree != '' and $html.quick-dirty != ''">
+            <xsl:apply-templates select="$version" mode="pruning">
+                <xsl:with-param name="target-node" select="//*[@id=$subtree]"/>
+            </xsl:apply-templates>
+        </xsl:when>
+        <xsl:otherwise>
+            <xsl:copy-of select="$version"/>
+        </xsl:otherwise>
+    </xsl:choose>
+</xsl:variable>
+<xsl:variable name="pruning-tree" select="exsl:node-set($pruning-tree-rtf)"/>
+
+<xsl:variable name="commentary-rtf">
+    <xsl:apply-templates select="$pruning-tree" mode="commentary"/>
+</xsl:variable>
+<xsl:variable name="commentaried" select="exsl:node-set($commentary-rtf)"/>
+
+<!-- A global list of all "webwork" used for       -->
+<!-- efficient backward-compatible indentification -->
+<xsl:variable name="all-webwork" select="$commentaried//webwork"/>
+
 <xsl:variable name="webwork-rtf">
     <xsl:apply-templates select="$commentaried" mode="webwork"/>
 </xsl:variable>
diff --git a/xsl/pretext-html.xsl b/xsl/pretext-html.xsl
index 8bf85222d..e09d006aa 100644
--- a/xsl/pretext-html.xsl
+++ b/xsl/pretext-html.xsl
@@ -103,6 +103,13 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
 <!-- Or make a thin customization layer and use 'select' to provide overrides -->
 <!-- See more generally applicable parameters in pretext-common.xsl file     -->
 
+<!-- Fast HTML build that skips steps inessential for quickly checking      -->
+<!-- changes to a document or a portion of a document.                      -->
+<!-- It will omit updating knowls, search index, theme, Runestone files,... -->
+<!-- When combined with param subtree, it will only process that subtree.   -->
+<xsl:param name="html.quick-dirty" select="''"/>
+<xsl:variable name="b-quick-dirty" select="not($html.quick-dirty = '')"/>
+
 <!-- CSS and Javascript Directories -->
 <!-- These are convenience variables to specify file prefixes  -->
 <!-- consistently.  If you know what you are doing you could   -->
@@ -261,15 +268,25 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
         </xsl:call-template>
     </xsl:if>
     <!--  -->
-    <xsl:apply-templates select="$original" mode="generic-warnings"/>
-    <xsl:apply-templates select="$original" mode="element-deprecation-warnings"/>
-    <xsl:apply-templates select="$original" mode="parameter-deprecation-warnings"/>
+    <xsl:choose>
+        <!-- if working on a subtree, only warn on that part -->
+        <xsl:when test="$b-quick-dirty and $b-subsetting">
+            <xsl:apply-templates select="$pruning-tree" mode="generic-warnings"/>
+            <xsl:apply-templates select="$pruning-tree" mode="element-deprecation-warnings"/>
+            <xsl:apply-templates select="$pruning-tree" mode="parameter-deprecation-warnings"/>
+        </xsl:when>
+        <xsl:otherwise>
+            <xsl:apply-templates select="$original" mode="generic-warnings"/>
+            <xsl:apply-templates select="$original" mode="element-deprecation-warnings"/>
+            <xsl:apply-templates select="$original" mode="parameter-deprecation-warnings"/>
+        </xsl:otherwise>
+    </xsl:choose>
     <!-- Usually no manifest is created -->
     <xsl:call-template name="runestone-manifest"/>
     <!-- A structured Table of Contents for a React app approach -->
     <xsl:call-template name="doc-manifest"/>
     <!-- build a search page (in development) -->
-    <xsl:if test="$has-native-search">
+    <xsl:if test="$has-native-search and not($b-quick-dirty)">
         <xsl:call-template name="search-page-construction"/>
     </xsl:if>
     <!-- The main event                          -->