diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a45ccf707..8a272f652c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,7 +14,7 @@ include(dtool/PandaMacros.cmake)
 include(dtool/PandaVersion.cmake)
 include(dtool/Packages.cmake)
 include(dtool/Config.cmake)
-#include(dtool/Interrogate.cmake)
+include(dtool/Interrogate.cmake)
 
 # Determine which trees to build.
 option(BUILD_DTOOL "Build the dtool source tree." ON)
diff --git a/dtool/CMakeLists.txt b/dtool/CMakeLists.txt
index 6422d57d5a..8c9761298a 100644
--- a/dtool/CMakeLists.txt
+++ b/dtool/CMakeLists.txt
@@ -13,3 +13,4 @@ add_subdirectory(src/interrogate)
 
 # Include dtool metalibs
 add_subdirectory(metalibs/dtool)
+add_subdirectory(metalibs/dtoolconfig)
diff --git a/dtool/Config.cmake b/dtool/Config.cmake
index f95cdcbceb..86393eac4e 100644
--- a/dtool/Config.cmake
+++ b/dtool/Config.cmake
@@ -213,6 +213,19 @@ FFI step.  This loads and runs much more quickly than the original
 mechanism.  Define this false (that is, empty) to use the original
 interfaces." ON)
 
+set(INTERROGATE_C_INTERFACE
+  "Do you want to generate a C-callable interrogate interface?  This
+generates an interface similar to the Python interface above, with
+a C calling convention.  It should be useful for most other kinds
+of scripting language; the VR Studio used to use this to make calls
+into Panda from Squeak." OFF)
+
+option(HAVE_INTERROGATE
+  "Do you even want to build interrogate at all?  This is the program
+that reads our C++ source files and generates one of the above
+interfaces.  If you won't be building the interfaces, you don't
+need the program." ON)
+
 set(INTERROGATE_OPTIONS "-fnames;-string;-refcount;-assert" CACHE STRING
   "What additional options should be passed to interrogate when
 generating either of the above two interfaces?  Generally, you
@@ -264,7 +277,7 @@ endif()
 
 option(USE_PYTHON
   "Enables support for Python.  If INTERROGATE_PYTHON_INTERFACE
-is also enabled, Python bindings will be generated.")
+is also enabled, Python bindings will be generated." ON)
 
 if(USE_PYTHON)
   find_package(PythonLibs)
diff --git a/dtool/Interrogate.cmake b/dtool/Interrogate.cmake
new file mode 100644
index 0000000000..e7b3ad9103
--- /dev/null
+++ b/dtool/Interrogate.cmake
@@ -0,0 +1,130 @@
+#
+# dtool/Interrogate.cmake
+#
+# This file contains macros and functions that are used to invoke
+# interrogate, in order to generate wrappers for Python and/or other
+# languages.
+#
+
+set(IGATE_FLAGS ${INTERROGATE_OPTIONS} -DCPPPARSER -D__cplusplus -Dvolatile -Dmutable)
+
+if(WIN32)
+  list(APPEND IGATE_FLAGS -longlong __int64 -D_X86_ -D__STDC__=1 -DWIN32_VC -D "_declspec(param)=" -D "__declspec(param)=" -D_near -D_far -D__near -D__far -D_WIN32 -D__stdcall -DWIN32)
+endif()
+if(INTERROGATE_VERBOSE)
+  list(APPEND IGATE_FLAGS "-v")
+endif()
+
+set(IMOD_FLAGS ${INTERROGATE_MODULE_OPTIONS})
+
+#
+# Function: target_interrogate(target [ALL] [source1 [source2 ...]])
+# NB. This doesn't actually invoke interrogate, but merely adds the
+# sources to the list of scan sources associated with the target.
+# Interrogate will be invoked when add_python_module is called.
+# If ALL is specified, all of the sources from the associated
+# target are added.
+#
+function(target_interrogate target)
+  if(HAVE_PYTHON AND HAVE_INTERROGATE)
+    set(sources)
+    set(want_all OFF)
+
+    # Find any .N files that would normally be picked up by interrogate.
+    # We let CMake add these as dependencies too, to allow rebuilding
+    # the wrappers when the .N files have been modified.
+    set(deps)
+    foreach(arg ${ARGV})
+      if(arg STREQUAL "ALL")
+        set(want_all ON)
+      else()
+        list(APPEND sources "${source}")
+      endif()
+    endforeach()
+
+    # If ALL was specified, pull in all sources from the target.
+    if(want_all)
+      get_target_property(target_sources "${target}" SOURCES)
+      list(APPEND sources ${target_sources})
+    endif()
+
+    list(REMOVE_DUPLICATES sources)
+
+    # Go through the sources to determine the full name,
+    # and also find out if there are any .N files to pick up.
+    foreach(source ${sources})
+      get_source_file_property(exclude "${source}" WRAP_EXCLUDE)
+
+      if(NOT exclude)
+        get_filename_component(basename "${source}" NAME_WE)
+        if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${basename}.N")
+          list(APPEND deps "${CMAKE_CURRENT_SOURCE_DIR}/${basename}.N")
+        endif()
+
+        # Add the full path to the source file itself.
+        get_source_file_property(location "${source}" LOCATION)
+        list(APPEND deps "${location}")
+      endif()
+    endforeach(source)
+
+    set_target_properties("${target}" PROPERTIES IGATE_SOURCES "${sources}")
+    set_target_properties("${target}" PROPERTIES IGATE_SRCDIR "${CMAKE_CURRENT_SOURCE_DIR}")
+    set_target_properties("${target}" PROPERTIES IGATE_DEPS "${deps}")
+  endif()
+endfunction(target_interrogate)
+
+#
+# Function: add_python_module(module [lib1 [lib2 ...]])
+# Uses interrogate to create a Python module.
+#
+function(add_python_module module)
+  if(HAVE_PYTHON AND HAVE_INTERROGATE)
+    set(targets ${ARGN})
+    set(infiles)
+    set(sources)
+
+    foreach(target ${targets})
+      get_target_property(scansrc "${target}" IGATE_SOURCES)
+      get_target_property(srcdir "${target}" IGATE_SRCDIR)
+      get_target_property(deps "${target}" IGATE_DEPS)
+
+      add_custom_command(
+        OUTPUT "${target}_igate.cxx" "${target}.in"
+        COMMAND interrogate
+          -od "${target}.in"
+          -oc "${target}_igate.cxx"
+          -module ${module} -library ${target} ${IGATE_FLAGS}
+          -srcdir "${srcdir}"
+          -I "${PROJECT_BINARY_DIR}/include"
+          -S "${PROJECT_SOURCE_DIR}/dtool/src/parser-inc"
+          -S "${PROJECT_BINARY_DIR}/include/parser-inc"
+          ${scansrc}
+        DEPENDS interrogate ${deps}
+      )
+
+      list(APPEND infiles "${target}.in")
+      list(APPEND sources "${target}_igate.cxx")
+    endforeach(target)
+
+    add_custom_command(
+      OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${module}_module.cxx"
+      COMMAND interrogate_module
+        -oc "${CMAKE_CURRENT_BINARY_DIR}/${module}_module.cxx"
+        -module ${module} -library ${module}
+        ${IMOD_FLAGS} ${infiles}
+      DEPENDS interrogate_module ${infiles}
+    )
+
+    add_library(${module} MODULE "${module}_module.cxx" ${sources})
+    target_link_libraries(${module} ${PYTHON_LIBRARIES})
+    target_link_libraries(${module} p3interrogatedb)
+
+    set_target_properties(${module} PROPERTIES
+      LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/panda3d"
+      PREFIX ""
+    )
+    if(WIN32 AND NOT CYGWIN)
+      set_target_properties(${module} PROPERTIES SUFFIX ".pyd")
+    endif()
+  endif()
+endfunction(add_python_module)
diff --git a/dtool/PandaMacros.cmake b/dtool/PandaMacros.cmake
index 0fea8d65d7..3c2d426ac4 100644
--- a/dtool/PandaMacros.cmake
+++ b/dtool/PandaMacros.cmake
@@ -1,7 +1,8 @@
 # Settings for composite builds.  Should be moved to Config.cmake?
-set(COMPOSITE_SOURCE_LIMIT "10" CACHE STRING
-  "Setting this to a value higher than 1 will enable unity builds.
-A high value will speed up the build dramatically but use more RAM.")
+set(COMPOSITE_SOURCE_LIMIT "30" CACHE STRING
+  "Setting this to a value higher than 1 will enable unity builds, also
+known as SCU (single compilation unit).  A high value will speed up the
+build dramatically but will be more memory intensive than a low value.")
 
 set(COMPOSITE_SOURCE_EXTENSIONS "cxx;c;mm" CACHE STRING
   "Only files of these extensions will be added to composite files.")
@@ -172,25 +173,28 @@ if(CMAKE_VERSION VERSION_LESS 2.8.11)
   endfunction()
 
   function(target_link_libraries target)
-    set(interface_dirs "")
+    set(interface_dirs)
     get_target_property(target_interface_dirs "${target}" INTERFACE_INCLUDE_DIRECTORIES)
 
     foreach(lib ${ARGN})
       get_target_property(lib_interface_dirs "${lib}" INTERFACE_INCLUDE_DIRECTORIES)
 
-      set(interface_dirs ${interface_dirs} ${lib_interface_dirs})
+      if(lib_interface_dirs)
+        list(APPEND interface_dirs ${lib_interface_dirs})
+      endif()
     endforeach()
 
+    list(REMOVE_DUPLICATES interface_dirs)
+
     #NB. target_include_directories is new in 2.8.8.
-    #target_include_directories("${target}" ${interace_dirs})
+    #target_include_directories("${target}" ${interface_dirs})
     include_directories(${interface_dirs})
-    message(STATUS "adding extra ${interface_dirs}")
 
     # Update this target's interface inc dirs.
     set_target_properties("${target}" PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${target_interface_dirs};${interface_dirs}")
 
     # Call to the built-in function we are overriding.
-    _target_link_libraries(${name} ${ARGN})
+    _target_link_libraries(${target} ${ARGN})
   endfunction()
 
 else()
diff --git a/dtool/metalibs/dtoolconfig/CMakeLists.txt b/dtool/metalibs/dtoolconfig/CMakeLists.txt
new file mode 100644
index 0000000000..22ed64ed6d
--- /dev/null
+++ b/dtool/metalibs/dtoolconfig/CMakeLists.txt
@@ -0,0 +1,8 @@
+if(HAVE_PYTHON)
+  add_library(p3dtoolconfig dtoolconfig.cxx pydtool.cxx)
+  target_link_libraries(p3dtoolconfig ${PYTHON_LIBRARIES})
+else()
+  add_library(p3dtoolconfig dtoolconfig.cxx)
+endif()
+
+target_link_libraries(p3dtoolconfig p3prc p3dconfig p3interrogatedb)
diff --git a/panda/CMakeLists.txt b/panda/CMakeLists.txt
index 75b940fa5b..13a678cbff 100644
--- a/panda/CMakeLists.txt
+++ b/panda/CMakeLists.txt
@@ -4,3 +4,5 @@ endif()
 
 # Include panda source directories
 add_subdirectory(src/pandabase)
+add_subdirectory(src/express)
+add_subdirectory(src/downloader)
diff --git a/panda/src/downloader/CMakeLists.txt b/panda/src/downloader/CMakeLists.txt
new file mode 100644
index 0000000000..7aad0126ad
--- /dev/null
+++ b/panda/src/downloader/CMakeLists.txt
@@ -0,0 +1,67 @@
+set(P3DOWNLOADER_HEADERS
+  bioPtr.I bioPtr.h
+  bioStreamPtr.I bioStreamPtr.h
+  bioStream.I bioStream.h bioStreamBuf.h
+  chunkedStream.I chunkedStream.h
+  chunkedStreamBuf.h chunkedStreamBuf.I
+  config_downloader.h
+  decompressor.h decompressor.I
+  documentSpec.h documentSpec.I
+  download_utils.h downloadDb.h downloadDb.I
+  extractor.h
+  httpAuthorization.I httpAuthorization.h
+  httpBasicAuthorization.I httpBasicAuthorization.h
+  httpChannel.I httpChannel.h
+  httpClient.I httpClient.h
+  httpCookie.I httpCookie.h
+  httpDate.I httpDate.h
+  httpDigestAuthorization.I httpDigestAuthorization.h
+  httpEntityTag.I httpEntityTag.h
+  httpEnum.h
+  identityStream.I identityStream.h
+  identityStreamBuf.h identityStreamBuf.I
+  multiplexStream.I multiplexStream.h
+  multiplexStreamBuf.I multiplexStreamBuf.h
+  patcher.h patcher.I
+  socketStream.h socketStream.I
+  stringStreamBuf.I stringStreamBuf.h
+  stringStream.I stringStream.h
+  urlSpec.h urlSpec.I
+  virtualFileHTTP.I virtualFileHTTP.h
+  virtualFileMountHTTP.I virtualFileMountHTTP.h)
+
+set(P3DOWNLOADER_SOURCES
+  config_downloader.cxx
+  bioPtr.cxx
+  bioStreamPtr.cxx
+  bioStream.cxx bioStreamBuf.cxx
+  chunkedStream.cxx chunkedStreamBuf.cxx
+  decompressor.cxx
+  documentSpec.cxx
+  downloadDb.cxx
+  download_utils.cxx
+  extractor.cxx
+  httpAuthorization.cxx
+  httpBasicAuthorization.cxx
+  httpChannel.cxx
+  httpClient.cxx
+  httpCookie.cxx
+  httpDate.cxx
+  httpDigestAuthorization.cxx
+  httpEntityTag.cxx
+  httpEnum.cxx
+  identityStream.cxx identityStreamBuf.cxx
+  multiplexStream.cxx multiplexStreamBuf.cxx
+  patcher.cxx
+  socketStream.cxx
+  stringStreamBuf.cxx
+  stringStream.cxx
+  urlSpec.cxx
+  virtualFileHTTP.cxx
+  virtualFileMountHTTP.cxx)
+
+composite_sources(p3downloader P3DOWNLOADER_SOURCES)
+
+add_library(p3downloader ${P3DOWNLOADER_SOURCES} ${P3DOWNLOADER_HEADERS})
+target_link_libraries(p3downloader p3express p3pandabase)
+target_interrogate(p3downloader ALL)
diff --git a/panda/src/express/CMakeLists.txt b/panda/src/express/CMakeLists.txt
new file mode 100644
index 0000000000..f1b4744eb4
--- /dev/null
+++ b/panda/src/express/CMakeLists.txt
@@ -0,0 +1,128 @@
+set(P3EXPRESS_HEADERS
+  buffer.I buffer.h
+  ca_bundle_data_src.c
+  checksumHashGenerator.I checksumHashGenerator.h circBuffer.I
+  circBuffer.h
+  compress_string.h
+  config_express.h
+  copy_stream.h
+  datagram.I datagram.h datagramGenerator.I
+  datagramGenerator.h
+  datagramIterator.I datagramIterator.h datagramSink.I datagramSink.h
+  dcast.T dcast.h
+  encrypt_string.h
+  error_utils.h
+  fileReference.h fileReference.I
+  hashGeneratorBase.I hashGeneratorBase.h
+  hashVal.I hashVal.h
+  indirectLess.I indirectLess.h
+  memoryInfo.I memoryInfo.h
+  memoryUsage.I memoryUsage.h
+  memoryUsagePointerCounts.I memoryUsagePointerCounts.h
+  memoryUsagePointers.I memoryUsagePointers.h
+  multifile.I multifile.h
+  namable.I
+  namable.h
+  nodePointerTo.h nodePointerTo.I
+  nodePointerToBase.h nodePointerToBase.I
+  nodeReferenceCount.h nodeReferenceCount.I
+  openSSLWrapper.h openSSLWrapper.I
+  ordered_vector.h ordered_vector.I ordered_vector.T
+  pStatCollectorForwardBase.h
+  password_hash.h
+  patchfile.I patchfile.h
+  pointerTo.I pointerTo.h
+  pointerToArray.I pointerToArray.h
+  pointerToArrayBase.I pointerToArrayBase.h
+  pointerToBase.I pointerToBase.h
+  pointerToVoid.I pointerToVoid.h
+  profileTimer.I profileTimer.h
+  pta_int.h
+  pta_uchar.h pta_double.h pta_float.h
+  pta_stdfloat.h
+  ramfile.I ramfile.h
+  referenceCount.I referenceCount.h
+  subStream.I subStream.h subStreamBuf.h
+  subfileInfo.h subfileInfo.I
+  temporaryFile.h temporaryFile.I
+  threadSafePointerTo.I threadSafePointerTo.h
+  threadSafePointerToBase.I threadSafePointerToBase.h
+  trueClock.I trueClock.h
+  typedReferenceCount.I typedReferenceCount.h typedef.h
+  vector_uchar.h vector_double.h vector_float.h
+  vector_stdfloat.h
+  virtualFile.I virtualFileList.I virtualFileList.h virtualFileMount.h
+  virtualFileComposite.h virtualFileComposite.I virtualFile.h
+  virtualFileMount.I virtualFileMountMultifile.h
+  virtualFileMountMultifile.I
+  virtualFileMountRamdisk.h virtualFileMountRamdisk.I
+  virtualFileMountSystem.h virtualFileMountSystem.I
+  virtualFileSimple.h virtualFileSimple.I
+  virtualFileSystem.h virtualFileSystem.I
+  weakPointerCallback.I weakPointerCallback.h
+  weakPointerTo.I weakPointerTo.h
+  weakPointerToBase.I weakPointerToBase.h
+  weakPointerToVoid.I weakPointerToVoid.h
+  weakReferenceList.I weakReferenceList.h
+  windowsRegistry.h
+  zStream.I zStream.h zStreamBuf.h)
+
+set(P3EXPRESS_SOURCES
+  buffer.cxx checksumHashGenerator.cxx
+  compress_string.cxx
+  config_express.cxx
+  copy_stream.cxx
+  datagram.cxx datagramGenerator.cxx
+  datagramIterator.cxx
+  datagramSink.cxx dcast.cxx
+  encrypt_string.cxx
+  error_utils.cxx
+  fileReference.cxx
+  hashGeneratorBase.cxx hashVal.cxx
+  memoryInfo.cxx memoryUsage.cxx memoryUsagePointerCounts.cxx
+  memoryUsagePointers.cxx multifile.cxx
+  namable.cxx
+  nodePointerTo.cxx
+  nodePointerToBase.cxx
+  nodeReferenceCount.cxx
+  openSSLWrapper.cxx
+  ordered_vector.cxx
+  pStatCollectorForwardBase.cxx
+  password_hash.cxx
+  patchfile.cxx
+  pointerTo.cxx
+  pointerToArray.cxx
+  pointerToBase.cxx
+  pointerToVoid.cxx
+  profileTimer.cxx
+  pta_int.cxx
+  pta_uchar.cxx pta_double.cxx pta_float.cxx
+  ramfile.cxx
+  referenceCount.cxx
+  subStream.cxx subStreamBuf.cxx
+  subfileInfo.cxx
+  temporaryFile.cxx
+  threadSafePointerTo.cxx
+  threadSafePointerToBase.cxx
+  trueClock.cxx
+  typedReferenceCount.cxx
+  vector_uchar.cxx vector_double.cxx vector_float.cxx
+  virtualFileComposite.cxx virtualFile.cxx virtualFileList.cxx
+  virtualFileMount.cxx
+  virtualFileMountMultifile.cxx
+  virtualFileMountRamdisk.cxx
+  virtualFileMountSystem.cxx
+  virtualFileSimple.cxx virtualFileSystem.cxx
+  weakPointerCallback.cxx
+  weakPointerTo.cxx
+  weakPointerToBase.cxx
+  weakPointerToVoid.cxx
+  weakReferenceList.cxx
+  windowsRegistry.cxx
+  zStream.cxx zStreamBuf.cxx)
+
+composite_sources(p3express P3EXPRESS_SOURCES)
+
+add_library(p3express ${P3EXPRESS_SOURCES} ${P3EXPRESS_HEADERS})
+target_link_libraries(p3express p3pandabase p3dtool p3dtoolconfig)
+target_interrogate(p3express ALL)