diff --git a/ISSUE_TEMPLATE.md b/.github/ISSUE_TEMPLATE.md
similarity index 100%
rename from ISSUE_TEMPLATE.md
rename to .github/ISSUE_TEMPLATE.md
diff --git a/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
similarity index 100%
rename from PULL_REQUEST_TEMPLATE.md
rename to .github/PULL_REQUEST_TEMPLATE.md
diff --git a/README.md b/README.md
index 67e41e162d2..1fd42861444 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,32 @@ Detailed instructions for installation in popular operating systems can be found
 -  [macOS](https://www.arduino.cc/en/Guide/MacOSX)
 -  [Windows](https://www.arduino.cc/en/Guide/Windows)
 
+## Contents of this repository
+
+This repository contains just the code for the Arduino IDE itself.
+Originally, it also contained the AVR and SAM Arduino core and libraries
+(i.e.  the code that is compiled as part of a sketch and runs on the
+actual Arduino device), but those have been moved into their own
+repositories.  They are still automatically downloaded as part of the
+build process and included in built releases, though.
+
+The repositories for these extra parts can be found here:
+-   Non-core specific Libraries are listed under: <https://github.com/arduino-libraries/>
+    (and also a few other places, see `build/build.xml`).
+
+-   The AVR core can be found at: <https://github.com/arduino/ArduinoCore-avr>
+
+-   Other cores are not included by default but installed through the
+    board manager. Their repositories can also be found under
+    <https://github.com/arduino/>.
+
+## Building and testing
+
+Instructions for building the IDE and running unit tests can be found on
+the wiki:
+-   <https://github.com/arduino/Arduino/wiki/Building-Arduino>
+-   <https://github.com/arduino/Arduino/wiki/Testing-Arduino>
+
 ## Credits
 
 Arduino is an open source project, supported by many.
diff --git a/build/build.xml b/build/build.xml
index 6ddec060203..2b08fff9263 100644
--- a/build/build.xml
+++ b/build/build.xml
@@ -237,10 +237,6 @@
 
   <!-- copy library folder -->
   <target name="assemble-libraries" unless="light_bundle">
-    <copy todir="${target.path}/libraries">
-      <fileset dir="../libraries"/>
-    </copy>
-
     <download-library name="Ethernet" version="2.0.0"/>
     <download-library name="GSM" version="1.0.6"/>
     <download-library name="Stepper" version="1.1.3"/>
diff --git a/lib_sync b/lib_sync
deleted file mode 100755
index 63419b00dee..00000000000
--- a/lib_sync
+++ /dev/null
@@ -1,48 +0,0 @@
-#!/bin/bash -ex
-
-git checkout master
-
-LIB=$1
-
-git branch lib_$LIB
-git checkout lib_$LIB
-
-git filter-branch -f --prune-empty --subdirectory-filter libraries/$LIB lib_$LIB
-
-cd ../libraries
-mkdir $LIB
-cd $LIB
-
-git init
-
-git pull ../../Arduino lib_$LIB
-
-git config user.email f.fissore@arduino.cc
-
-git filter-branch -f --commit-filter 'if [ "$GIT_AUTHOR_EMAIL" = "f.vanzati@gmail.com" ];
-  then export GIT_AUTHOR_EMAIL=f.vanzati@arduino.cc;
-  fi; git commit-tree "$@"'
-git filter-branch -f --commit-filter 'if [ "$GIT_AUTHOR_EMAIL" = "federico@fissore.org" ];
-  then export GIT_AUTHOR_EMAIL=f.fissore@arduino.cc;
-  fi; git commit-tree "$@"'
-git filter-branch -f --commit-filter 'if [ "$GIT_AUTHOR_EMAIL" = "c.maglie@bug.st" ];
-  then export GIT_AUTHOR_EMAIL=c.maglie@arduino.cc;
-  fi; git commit-tree "$@"'
-git filter-branch -f --commit-filter 'if [ "$GIT_AUTHOR_EMAIL" = "tigoe@tigoemac.itp.tsoa.nyu.edu" ];
-  then export GIT_AUTHOR_EMAIL=t.igoe@arduino.cc;
-  fi; git commit-tree "$@"'
-git filter-branch -f --commit-filter 'if [ "$GIT_AUTHOR_EMAIL" = "tom.igoe@gmail.com" ];
-  then export GIT_AUTHOR_EMAIL=t.igoe@arduino.cc;
-  fi; git commit-tree "$@"'
-git filter-branch -f --commit-filter 'if [ "$GIT_AUTHOR_EMAIL" = "facchinm@users.noreply.github.com" ];
-  then export GIT_AUTHOR_EMAIL=m.facchin@arduino.cc;
-  fi; git commit-tree "$@"'
-
-git remote add origin git@github.com:arduino-libraries/$LIB.git
-git fetch --all
-
-cd ../../Arduino
-
-git checkout master
-git branch -D lib_$LIB
-
diff --git a/libraries/.keep b/libraries/.keep
deleted file mode 100644
index e69de29bb2d..00000000000