diff --git a/build/gecko_templates.mozbuild b/build/gecko_templates.mozbuild
index 81030551df43..e108f5415a87 100644
--- a/build/gecko_templates.mozbuild
+++ b/build/gecko_templates.mozbuild
@@ -55,19 +55,27 @@ def GeckoBinary(linkage='dependent', msvcrt='dynamic', mozglue=None):
         error('`linkage` must be "dependent", "standalone" or None')
 
     if mozglue:
-        LDFLAGS += CONFIG['MOZ_GLUE_WRAP_LDFLAGS']
-        if mozglue == 'program':
-            USE_LIBS += ['mozglue']
-            if CONFIG['MOZ_GLUE_IN_PROGRAM']:
-                if CONFIG['GNU_CC']:
-                    LDFLAGS += ['-rdynamic']
-                if CONFIG['MOZ_MEMORY']:
-                    USE_LIBS += ['memory']
-        elif mozglue == 'library':
-            if not CONFIG['MOZ_GLUE_IN_PROGRAM']:
+        if CONFIG['MOZ_CRT']:
+            if msvcrt == 'dynamic':
+                USE_LIBS += ['mozcrt']
+            elif msvcrt == 'static':
                 USE_LIBS += ['mozglue']
+            else:
+                error('`msvcrt` must be "dynamic" or "static"')
         else:
-            error('`mozglue` must be "program" or "library"')
+            LDFLAGS += CONFIG['MOZ_GLUE_WRAP_LDFLAGS']
+            if mozglue == 'program':
+                USE_LIBS += ['mozglue']
+                if CONFIG['MOZ_GLUE_IN_PROGRAM']:
+                    if CONFIG['GNU_CC']:
+                        LDFLAGS += ['-rdynamic']
+                    if CONFIG['MOZ_MEMORY']:
+                        USE_LIBS += ['memory']
+            elif mozglue == 'library':
+                if not CONFIG['MOZ_GLUE_IN_PROGRAM']:
+                    USE_LIBS += ['mozglue']
+            else:
+                error('`mozglue` must be "program" or "library"')
 
     if not CONFIG['JS_STANDALONE']:
         USE_LIBS += [
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 63853f0f3d35..12a59f662fdb 100644
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -541,12 +541,13 @@ def compiler(language, host_or_target, c_compiler=None, other_compiler=None,
                 'Only clang/llvm 3.4 or newer is supported.')
 
         if info.type == 'msvc':
-            if info.version < '19.00.23918':
+            if info.version < '18.00.30723' or (
+                    '19' < info.version < '19.00.23506'):
                 raise FatalCheckError(
                     'This version (%s) of the MSVC compiler is not '
                     'supported.\n'
-                    'You must install Visual C++ 2015 Update 2 or newer in '
-                    'order to build.\n'
+                    'You must install Visual C++ 2013 Update 3, Visual '
+                    'C++ 2015 Update 1, or newer in order to build.\n'
                     'See https://developer.mozilla.org/en/'
                     'Windows_Build_Prerequisites' % info.version)
 
diff --git a/build/win32/mozconfig.vs2013-win64 b/build/win32/mozconfig.vs2013-win64
new file mode 100644
index 000000000000..85821f0720aa
--- /dev/null
+++ b/build/win32/mozconfig.vs2013-win64
@@ -0,0 +1,23 @@
+_VSPATH="/c/tools/vs2013"
+export WIN32_REDIST_DIR=${_VSPATH}/VC/redist/x86/Microsoft.VC120.CRT
+
+## includes: win8.1 sdk includes, msvc std library, directx sdk for d3d9 ##
+export INCLUDE=/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/include/shared:/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/include/um:/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/include/winrt:${_VSPATH}/vc/include:${_VSPATH}/vc/atlmfc/include:/c/tools/sdks/dx10/include
+
+## libs: win8.1 sdk x86 (32-bit) libs, msvc (32-bit) std library, msvc atl libs, directx sdk (32-bit) for d3d9  ##
+export LIBPATH=/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/Lib/winv6.3/um/x86:${_VSPATH}/vc/lib:${_VSPATH}/vc/atlmfc/lib:/c/tools/sdks/dx10/lib
+export LIB=/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/Lib/winv6.3/um/x86:${_VSPATH}/vc/lib:${_VSPATH}/vc/atlmfc/lib:/c/tools/sdks/dx10/lib
+
+## paths: win8.1 sdk x86 (32-bit) tools, msvc (64-bit compiling 32-bit) build toolchain, moz tools  ##
+export PATH="/c/Program Files (x86)/Windows Kits/8.1/bin/x86:${_VSPATH}/Common7/IDE:${_VSPATH}/VC/BIN/amd64_x86:${_VSPATH}/VC/BIN/amd64:${_VSPATH}/Common7/Tools:${_VSPATH}/VC/VCPackages:/c/mozilla-build/moztools:${PATH}"
+
+## WindowsSDKDir ##
+export WINDOWSSDKDIR="/c/Program Files (x86)/Windows Kits/8.1/"
+
+. $topsrcdir/build/mozconfig.vs-common
+
+mk_export_correct_style LIB
+mk_export_correct_style LIBPATH
+mk_export_correct_style PATH
+mk_export_correct_style INCLUDE
+mk_export_correct_style WIN32_REDIST_DIR
diff --git a/build/win64/mozconfig.vs2013 b/build/win64/mozconfig.vs2013
new file mode 100644
index 000000000000..5fbde2df738b
--- /dev/null
+++ b/build/win64/mozconfig.vs2013
@@ -0,0 +1,23 @@
+_VSPATH="/c/tools/vs2013"
+export WIN32_REDIST_DIR=${_VSPATH}/VC/redist/x64/Microsoft.VC120.CRT
+
+## includes: win8.1 sdk includes, msvc std library, directx sdk for d3d9 ##
+export INCLUDE=/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/include/shared:/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/include/um:/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/include/winrt:${_VSPATH}/vc/include:${_VSPATH}/vc/atlmfc/include:/c/tools/sdks/dx10/include
+
+## libs: win8.1 sdk x64 (64-bit) libs, msvc (64-bit) std library, msvc atl libs, directx sdk (64-bit) for d3d9  ##
+export LIBPATH=/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/Lib/winv6.3/um/x64:${_VSPATH}/vc/lib/amd64:${_VSPATH}/vc/atlmfc/lib/amd64:/c/tools/sdks/dx10/lib/x64
+export LIB=/c/Program\ Files\ \(x86\)/Windows\ Kits/8.1/Lib/winv6.3/um/x64:${_VSPATH}/vc/lib/amd64:${_VSPATH}/vc/atlmfc/lib/amd64:/c/tools/sdks/dx10/lib/x64
+
+## paths: win8.1 sdk x64 (64-bit) tools, msvc (64-bit) build toolchain, moz tools  ##
+export PATH="/c/Program Files (x86)/Windows Kits/8.1/bin/x64:${_VSPATH}/Common7/IDE:${_VSPATH}/VC/BIN/amd64:${_VSPATH}/VC/BIN/x86_amd64:${_VSPATH}/VC/BIN:${_VSPATH}/Common7/Tools:${_VSPATH}/VC/VCPackages:${PATH}"
+
+## WindowsSDKDir ##
+export WINDOWSSDKDIR="/c/Program Files (x86)/Windows Kits/8.1/"
+
+. $topsrcdir/build/mozconfig.vs-common
+
+mk_export_correct_style LIB
+mk_export_correct_style LIBPATH
+mk_export_correct_style PATH
+mk_export_correct_style INCLUDE
+mk_export_correct_style WIN32_REDIST_DIR
diff --git a/config/external/nss/Makefile.in b/config/external/nss/Makefile.in
index b3a17bfea5fa..f3f3abe25155 100644
--- a/config/external/nss/Makefile.in
+++ b/config/external/nss/Makefile.in
@@ -367,7 +367,12 @@ endif
 # Can't pass this in DEFAULT_GMAKE_FLAGS because that overrides
 # definitions in NSS, so just export it into the sub-make's environment.
 ifeq (WINNT_1,$(OS_TARGET)_$(MOZ_MEMORY))
+ifdef MOZ_CRT
+# OS_LIBS comes from having mozcrt as a dependency in moz.build.
+DLLFLAGS := $(OS_LIBS)
+else
 DLLFLAGS := -LIBPATH:$(ABS_DIST)/../mozglue/build -DEFAULTLIB:mozglue
+endif
 export DLLFLAGS
 endif
 
diff --git a/config/recurse.mk b/config/recurse.mk
index 998c9310bb97..6316f7c27f72 100644
--- a/config/recurse.mk
+++ b/config/recurse.mk
@@ -168,6 +168,9 @@ endif
 ifeq ($(MOZ_REPLACE_MALLOC_LINKAGE),dummy library)
 mozglue/build/target memory/replace/logalloc/replay/target: memory/replace/dummy/target
 endif
+ifdef MOZ_CRT
+mozglue/crt/target: mozglue/build/target
+endif
 # js/src/target can end up invoking js/src/host rules (through object files
 # depending on jsautokw.h, which depends on host_jskwgen, and that can't
 # happen at the same time (bug #1146738)
diff --git a/js/src/old-configure.in b/js/src/old-configure.in
index 5900f889e08a..9c8ff3583601 100644
--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -215,6 +215,12 @@ case "$target" in
         AC_DEFINE(_USE_MATH_DEFINES) # Otherwise MSVC's math.h doesn't #define M_PI.
 
         case "$CC_VERSION" in
+        18*)
+            _CC_SUITE=12
+            MSVS_VERSION=2013
+            MSVC_C_RUNTIME_DLL=msvcr120.dll
+            MSVC_CXX_RUNTIME_DLL=msvcp120.dll
+            ;;
         19*)
             _CC_SUITE=14
             MSVS_VERSION=2015
@@ -1909,6 +1915,7 @@ if test "$MOZ_MEMORY"; then
     ;;
   esac
 fi
+AC_SUBST(MOZ_CRT)
 AC_SUBST(MOZ_GLUE_IN_PROGRAM)
 AC_SUBST_LIST(MOZ_GLUE_WRAP_LDFLAGS)
 
diff --git a/mozglue/build/moz.build b/mozglue/build/moz.build
index 26fc0799766b..1183320c57e0 100644
--- a/mozglue/build/moz.build
+++ b/mozglue/build/moz.build
@@ -11,7 +11,8 @@ if CONFIG['OS_TARGET'] in ('WINNT', 'Darwin', 'Android'):
 else:
     Library('mozglue')
 
-SDK_LIBRARY = True
+if not CONFIG['MOZ_CRT']:
+    SDK_LIBRARY = True
 
 if CONFIG['OS_TARGET'] == 'Android':
     SOURCES += [
diff --git a/mozglue/crt/Makefile.in b/mozglue/crt/Makefile.in
new file mode 100644
index 000000000000..b1628b151729
--- /dev/null
+++ b/mozglue/crt/Makefile.in
@@ -0,0 +1,89 @@
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Roll our own custom logic here for the import library
+
+###############################################################################
+#
+# Linking Mozilla itself to jemalloc is not particularly difficult.  To do this
+# we avoid linking directly to the Microsoft-provided CRT import libraries.
+# Instead, we link to our own import library which we generate here.  To
+# replace the CRT's malloc/free/other memory management symbols we export
+# our own versions out of jemalloc.dll.  We then take the import library that
+# the compiler generates for jemalloc.dll and combine it with the MS CRT import
+# libraries.  We put our library on the command line first, and the CRT symbols
+# are discarded in favor of our versions!
+#
+# Unfortunately that was too easy.  The CRT import library is not a standard
+# import library that contains a list of symbols and whatnot.  It also includes
+# object files that are linked into generated programs.  One of these,
+# crtdll.obj is (as one might expect) linked into all DLLs that link against
+# the CRT.  This file does things like run static C++ constructors when the
+# DLL is attached, call DllMain, etc.
+#
+# In the CRT source all malloc/free calls are made to malloc_crt and free_crt.
+# In debug builds these are both defined to malloc_dbg and free_dbg.  In opt
+# builds malloc_crt is an actual function, implemented and exposed from the
+# CRT.  free_crt is, however, defined to be just plain old free.  This works
+# fine inside the CRT where malloc_crt and free operate on the same heap.
+# Outside the CRT malloc_crt is in the CRT's heap, but free is in jemalloc's
+# heap.  This causes much pain at shutdown :-(
+#
+# The obvious solution here is to override malloc_crt too.  Unfortunately,
+# that doesn't work because the CRT expects to be able to call msize on this
+# piece of memory deep inside the CRT, which will fail because it'll call the
+# CRT's msize on a pointer in jemalloc's heap.
+#
+# Our solution to this is quite devious.  We take apart the CRT's import lib
+# and remove the problematic object file.  We then poke at the object file's
+# symbol table and replace '__imp__free' (which means grab free from some
+# other DLL) with '__imp__frex'.  Then we define our own dummy no-op function
+# in jemalloc.dll and export it as frex.  Then we put the CRT import lib
+# back together with the patched crtdll.obj, glue it to the end of jemalloc's
+# import library and link the rest of Mozilla to that.
+#
+# The result?  A binary that uses jemalloc, doesn't crash, and leaks a tiny
+# amount of memory (32 words per DLL in the 2010 CRT) at shutdown.
+#
+###############################################################################
+
+target:: mozcrt.lib
+	$(INSTALL) $(IFLAGS2) mozcrt.lib $(DIST)/lib
+
+# And finally combine that with the jemalloc import library to get an import
+# library that has our malloc/free/etc and the CRT's everything else
+mozcrt.lib: ../build/mozglue.lib msvc_modified.lib
+	lib -OUT:$@ $^
+
+# Put the fixed object file back in
+msvc_modified.lib: msvc_removed.lib crtdll_fixed.obj
+	lib -OUT:$@ $^
+
+# Fix the object file
+crtdll_fixed.obj: crtdll.obj
+	$(PYTHON) $(srcdir)/fixcrt.py
+
+# Find the path of crtdll.obj
+CRTDLL_FULLPATH=$(subst \,\\,$(shell lib -list msvc_combined.lib | grep crtdll\\.obj))
+
+# Remove the broken object file, only after we have extracted it
+msvc_removed.lib: msvc_combined.lib crtdll.obj
+	lib -OUT:$@ msvc_combined.lib -REMOVE:$(CRTDLL_FULLPATH)
+
+# Extract the broken object file out of the combined library
+crtdll.obj: msvc_combined.lib
+	lib -OUT:$@ $^ -EXTRACT:$(CRTDLL_FULLPATH)
+
+# Grab both CRT libraries and combine them into one library to simplify things
+msvc_combined.lib:
+	lib -OUT:$@ $(WIN32_CRT_LIBS)
+
+# Normally, we'd use SDK_LIBRARY, but we can't because all the tricks above
+# involve *not* defining the library in moz.build, so SDK_LIBRARY = True would
+# not have the expected outcome.
+SDK_FILES = mozcrt.lib
+SDK_DEST = $(SDK_LIB_DIR)
+SDK_TARGET = target
+INSTALL_TARGETS += SDK
diff --git a/mozglue/crt/fixcrt.py b/mozglue/crt/fixcrt.py
new file mode 100644
index 000000000000..3baa935f22a7
--- /dev/null
+++ b/mozglue/crt/fixcrt.py
@@ -0,0 +1,14 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import with_statement
+
+with open('crtdll.obj', 'rb') as infile:
+  data = infile.read()
+  with open('crtdll_fixed.obj', 'wb') as outfile:
+    # for Win32
+    data = data.replace('__imp__free', '__imp__frex')
+    # for Win64
+    data = data.replace('__imp_free', '__imp_frex')
+    outfile.write(data)
diff --git a/mozglue/crt/moz.build b/mozglue/crt/moz.build
new file mode 100644
index 000000000000..b0084367bf35
--- /dev/null
+++ b/mozglue/crt/moz.build
@@ -0,0 +1,16 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Library('mozcrt')
+
+STATIC_LIBRARY_NAME = 'mozcrt_s'
+
+OS_LIBS += [
+    '-NODEFAULTLIB:msvcrt',
+    '-NODEFAULTLIB:msvcprt',
+    '-LIBPATH:%s/mozglue/crt' % TOPOBJDIR,
+    '-DEFAULTLIB:mozcrt',
+]
diff --git a/mozglue/moz.build b/mozglue/moz.build
index 0938dc37282a..d2fa07e814de 100644
--- a/mozglue/moz.build
+++ b/mozglue/moz.build
@@ -15,5 +15,8 @@ DIRS += [
   'misc',
 ]
 
+if CONFIG['MOZ_CRT']:
+    DIRS += ['crt']
+
 if not CONFIG['JS_STANDALONE']:
     TEST_DIRS += ['tests']
diff --git a/old-configure.in b/old-configure.in
index 56736ffd401c..064e7596a33a 100644
--- a/old-configure.in
+++ b/old-configure.in
@@ -321,6 +321,12 @@ case "$target" in
         AC_DEFINE(_USE_MATH_DEFINES) # Otherwise MSVC's math.h doesn't #define M_PI.
 
         case "$CC_VERSION" in
+        18*)
+            _CC_SUITE=12
+            MSVS_VERSION=2013
+            MSVC_C_RUNTIME_DLL=msvcr120.dll
+            MSVC_CXX_RUNTIME_DLL=msvcp120.dll
+            ;;
         19*)
             _CC_SUITE=14
             MSVS_VERSION=2015
@@ -5394,11 +5400,24 @@ else
   case "${target}" in
   *-mingw*)
     export MOZ_NO_DEBUG_RTL=1
+    if test "$MSVS_VERSION" != "2015"; then
+        WIN32_CRT_LIBS="msvcrt.lib msvcprt.lib"
+        dnl Look for a broken crtdll.obj
+        WIN32_CRTDLL_FULLPATH=`lib -nologo -list $WIN32_CRT_LIBS | grep crtdll\\.obj`
+        lib -NOLOGO -OUT:crtdll.obj $WIN32_CRT_LIBS -EXTRACT:$WIN32_CRTDLL_FULLPATH
+        if grep -q '__imp__\{0,1\}free' crtdll.obj; then
+          MOZ_CRT=1
+        fi
+        rm crtdll.obj
+    fi
     ;;
   esac
 fi # MOZ_MEMORY
 AC_SUBST(MOZ_SYSTEM_JEMALLOC)
+AC_SUBST(MOZ_CRT)
+export MOZ_CRT
 AC_SUBST(MOZ_GLUE_IN_PROGRAM)
+AC_SUBST_LIST(WIN32_CRT_LIBS)
 
 # Allow the application to provide a subconfigure script.
 # This should be after 'export MOZ_NO_DEBUG_RTL=1' since
diff --git a/python/mozbuild/mozbuild/backend/visualstudio.py b/python/mozbuild/mozbuild/backend/visualstudio.py
index 86e97d13d3ce..f5271a773e53 100644
--- a/python/mozbuild/mozbuild/backend/visualstudio.py
+++ b/python/mozbuild/mozbuild/backend/visualstudio.py
@@ -38,13 +38,17 @@ def get_id(name):
     return str(uuid.uuid5(uuid.NAMESPACE_URL, name)).upper()
 
 def visual_studio_product_to_solution_version(version):
-    if version == '2015':
+    if version == '2013':
+        return '12.00', '12'
+    elif version == '2015':
         return '12.00', '14'
     else:
         raise Exception('Unknown version seen: %s' % version)
 
 def visual_studio_product_to_platform_toolset_version(version):
-    if version == '2015':
+    if version == '2013':
+        return 'v120'
+    elif version == '2015':
         return 'v140'
     else:
         raise Exception('Unknown version seen: %s' % version)