diff --git a/src/Composer/InstalledVersions.php b/src/Composer/InstalledVersions.php
index e6df5a5a2..5126c5f8b 100644
--- a/src/Composer/InstalledVersions.php
+++ b/src/Composer/InstalledVersions.php
@@ -24,10 +24,15 @@ use Composer\Semver\VersionParser;
  */
 class InstalledVersions
 {
-    private static $installed;
+    private static $installed = array();
     private static $canGetVendors;
     private static $installedByVendor = array();
 
+    /**
+     * Initialize $installed array
+     */
+    public static function initializeInstalled() {}
+
     /**
      * Returns a list of all package names which are present, either by being installed, replaced or provided
      *
@@ -48,6 +53,28 @@ class InstalledVersions
         return array_keys(array_flip(\call_user_func_array('array_merge', $packages)));
     }
 
+    /**
+     * Returns a list of all package names with a specific type e.g. 'library'
+     *
+     * @param  string   $type
+     * @return string[]
+     * @psalm-return list<string>
+     */
+    public static function getInstalledPackagesByType($type)
+    {
+        $packagesByType = array();
+
+        foreach (self::getInstalled() as $installed) {
+            foreach ($installed['versions'] as $name => $package) {
+                if (isset($package['type']) && $package['type'] === $type) {
+                    $packagesByType[] = $name;
+                }
+            }
+        }
+
+        return $packagesByType;
+    }
+
     /**
      * Checks whether the given package is installed
      *
@@ -274,3 +301,5 @@ class InstalledVersions
         return $installed;
     }
 }
+
+InstalledVersions::initializeInstalled();
diff --git a/src/Composer/Repository/FilesystemRepository.php b/src/Composer/Repository/FilesystemRepository.php
index fefc52dfe..99af09be7 100644
--- a/src/Composer/Repository/FilesystemRepository.php
+++ b/src/Composer/Repository/FilesystemRepository.php
@@ -14,6 +14,7 @@ namespace Composer\Repository;
 
 use Composer\Json\JsonFile;
 use Composer\Package\Loader\ArrayLoader;
+use Composer\Package\PackageInterface;
 use Composer\Package\RootPackageInterface;
 use Composer\Package\AliasPackage;
 use Composer\Package\Dumper\ArrayDumper;
@@ -102,11 +103,15 @@ class FilesystemRepository extends WritableArrayRepository
         $dumper = new ArrayDumper();
         $fs = new Filesystem();
         $repoDir = dirname($fs->normalizePath($this->file->getPath()));
+        $installPaths = array();
 
         foreach ($this->getCanonicalPackages() as $package) {
             $pkgArray = $dumper->dump($package);
             $path = $installationManager->getInstallPath($package);
-            $pkgArray['install-path'] = ('' !== $path && null !== $path) ? $fs->findShortestPath($repoDir, $fs->isAbsolutePath($path) ? $path : getcwd() . '/' . $path, true) : null;
+            $installPath = ('' !== $path && null !== $path) ? $fs->findShortestPath($repoDir, $fs->isAbsolutePath($path) ? $path : getcwd() . '/' . $path, true) : null;
+            $installPaths[$package->getName()] = $installPath;
+
+            $pkgArray['install-path'] = $installPath;
             $data['packages'][] = $pkgArray;
 
             // only write to the files the names which are really installed, as we receive the full list
@@ -124,24 +129,56 @@ class FilesystemRepository extends WritableArrayRepository
         $this->file->write($data);
 
         if ($this->dumpVersions) {
-            $versions = $this->generateInstalledVersions($installationManager, $devMode);
+            $versions = $this->generateInstalledVersions($installationManager, $installPaths, $devMode, $repoDir);
 
-            $fs->filePutContentsIfModified($repoDir.'/installed.php', '<?php return '.var_export($versions, true).';'."\n");
+            $fs->filePutContentsIfModified($repoDir.'/installed.php', '<?php return ' . $this->dumpVersion($versions) . ';'."\n");
             $installedVersionsClass = file_get_contents(__DIR__.'/../InstalledVersions.php');
             // while not strictly needed since https://github.com/composer/composer/pull/9635 - we keep this for BC
             // and overall broader compatibility with people that may not use Composer's ClassLoader. They can
             // simply include InstalledVersions.php manually and have it working in a basic way.
-            $installedVersionsClass = str_replace('private static $installed;', 'private static $installed = '.var_export($versions, true).';', $installedVersionsClass);
+            $installedVersionsClass = str_replace('public static function initializeInstalled() {}', 'public static function initializeInstalled() {' . PHP_EOL . 'self::$installed = ' . $this->dumpVersion($versions) . ';' . PHP_EOL . '}', $installedVersionsClass);
             $fs->filePutContentsIfModified($repoDir.'/InstalledVersions.php', $installedVersionsClass);
 
             \Composer\InstalledVersions::reload($versions);
         }
     }
 
+    private function dumpVersion(array $array = array(), $level = 0)
+    {
+        $lines = "array(\n";
+        $level++;
+
+        foreach ($array as $key => $value) {
+            $lines .= str_repeat('    ', $level);
+            $lines .= is_int($key) ? $key . ' => ' : '\'' . $key . '\' => ';
+
+            if (is_array($value)) {
+                if (!empty($value)) {
+                    $lines .= self::dumpVersion($value, $level);
+                } else {
+                    $lines .= "array(),\n";
+                }
+            }  elseif (is_null($value)) {
+                $lines .= 'null';
+                $lines .= ",\n";
+            }  elseif (is_bool($value)) {
+                $lines .= $value ? 'true' : 'false';
+                $lines .= ",\n";
+            } else {
+                $stringContent = str_replace(array('\\', '\''), array('\\\\', '\\\''), $value);
+                $folder = $key === 'install_path' ? '__DIR__ . DIRECTORY_SEPARATOR . ' : '';
+                $lines .= $folder . "'" . $stringContent . "',\n";
+            }
+        }
+
+        $lines .= str_repeat('    ', $level - 1) . ')' . ($level - 1 == 0 ? '' : ",\n");
+        return $lines;
+    }
+
     /**
      * @return ?array
      */
-    private function generateInstalledVersions(InstallationManager $installationManager, $devMode)
+    private function generateInstalledVersions(InstallationManager $installationManager, $installPaths, $devMode, $repoDir)
     {
         if (!$this->dumpVersions) {
             return null;
@@ -170,9 +207,19 @@ class FilesystemRepository extends WritableArrayRepository
                 $reference = ($package->getSourceReference() ?: $package->getDistReference()) ?: null;
             }
 
+            if($package instanceof RootPackageInterface) {
+                $fs = new Filesystem();
+                $to = getcwd();
+                $installPath = $fs->findShortestPath($repoDir, $to, true);
+            } else {
+                $installPath = $installPaths[$package->getName()];
+            }
+
             $versions['versions'][$package->getName()] = array(
                 'pretty_version' => $package->getPrettyVersion(),
                 'version' => $package->getVersion(),
+                'type' => $package->getType(),
+                'install_path' => $installPath,
                 'aliases' => array(),
                 'reference' => $reference,
                 'dev-requirement' => isset($devPackages[$package->getName()]),
diff --git a/tests/Composer/Test/InstalledVersionsTest.php b/tests/Composer/Test/InstalledVersionsTest.php
index 7896548e2..bfd7feb78 100644
--- a/tests/Composer/Test/InstalledVersionsTest.php
+++ b/tests/Composer/Test/InstalledVersionsTest.php
@@ -17,6 +17,8 @@ use Composer\Semver\VersionParser;
 
 class InstalledVersionsTest extends TestCase
 {
+    private $root;
+
     public static function setUpBeforeClass()
     {
         // disable multiple-ClassLoader-based checks of InstalledVersions by making it seem like no
@@ -33,6 +35,9 @@ class InstalledVersionsTest extends TestCase
 
     public function setUp()
     {
+        $this->root = $this->getUniqueTmpDirectory();
+
+        $dir = $this->root;
         InstalledVersions::reload(require __DIR__.'/Repository/Fixtures/installed.php');
     }
 
@@ -187,6 +192,8 @@ class InstalledVersionsTest extends TestCase
         $this->assertSame(array(
             'pretty_version' => 'dev-master',
             'version' => 'dev-master',
+            'type' => 'library',
+            'install_path' => $this->root . DIRECTORY_SEPARATOR . './',
             'aliases' => array(
                 '1.10.x-dev',
             ),
@@ -198,6 +205,7 @@ class InstalledVersionsTest extends TestCase
 
     public function testGetRawData()
     {
+        $dir = $this->root;
         $this->assertSame(require __DIR__.'/Repository/Fixtures/installed.php', InstalledVersions::getRawData());
     }
 
@@ -222,4 +230,17 @@ class InstalledVersionsTest extends TestCase
             array(null, 'c/c'),
         );
     }
+
+    public function testGetInstalledPackagesByType()
+    {
+        $names = array(
+            '__root__',
+            'a/provider',
+            'a/provider2',
+            'b/replacer',
+            'c/c',
+        );
+
+        $this->assertSame($names, \Composer\InstalledVersions::getInstalledPackagesByType('library'));
+    }
 }
diff --git a/tests/Composer/Test/Mock/InstallationManagerMock.php b/tests/Composer/Test/Mock/InstallationManagerMock.php
index 4642a4800..7898250cc 100644
--- a/tests/Composer/Test/Mock/InstallationManagerMock.php
+++ b/tests/Composer/Test/Mock/InstallationManagerMock.php
@@ -119,4 +119,9 @@ class InstallationManagerMock extends InstallationManager
     {
         // noop
     }
+
+    public function getInstalledPackagesByType()
+    {
+        return $this->installed;
+    }
 }
diff --git a/tests/Composer/Test/Repository/FilesystemRepositoryTest.php b/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
index 72e7adfa3..41d6ff0c1 100644
--- a/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
+++ b/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
@@ -18,6 +18,8 @@ use Composer\Json\JsonFile;
 
 class FilesystemRepositoryTest extends TestCase
 {
+    private $root;
+
     public function testRepositoryRead()
     {
         $json = $this->createJsonFileMock();
@@ -121,6 +123,9 @@ class FilesystemRepositoryTest extends TestCase
     public function testRepositoryWritesInstalledPhp()
     {
         $dir = $this->getUniqueTmpDirectory();
+        $this->root = $dir;
+        chdir($dir);
+
         $json = new JsonFile($dir.'/installed.json');
 
         $rootPackage = $this->getPackage('__root__', 'dev-master', 'Composer\Package\RootPackage');
diff --git a/tests/Composer/Test/Repository/Fixtures/installed.php b/tests/Composer/Test/Repository/Fixtures/installed.php
index 8c6c148ae..0f6283c7e 100644
--- a/tests/Composer/Test/Repository/Fixtures/installed.php
+++ b/tests/Composer/Test/Repository/Fixtures/installed.php
@@ -14,6 +14,9 @@ return array(
     'root' => array(
         'pretty_version' => 'dev-master',
         'version' => 'dev-master',
+        'type' => 'library',
+        // @phpstan-ignore-next-line
+        'install_path' => $dir . DIRECTORY_SEPARATOR . './',
         'aliases' => array(
             '1.10.x-dev',
         ),
@@ -25,6 +28,9 @@ return array(
         '__root__' => array(
             'pretty_version' => 'dev-master',
             'version' => 'dev-master',
+            'type' => 'library',
+            // @phpstan-ignore-next-line
+            'install_path' => $dir . DIRECTORY_SEPARATOR . './',
             'aliases' => array(
                 '1.10.x-dev',
             ),
@@ -34,6 +40,9 @@ return array(
         'a/provider' => array(
             'pretty_version' => '1.1',
             'version' => '1.1.0.0',
+            'type' => 'library',
+            // @phpstan-ignore-next-line
+            'install_path' => $dir . DIRECTORY_SEPARATOR . '/foo/bar/vendor/woop/woop',
             'aliases' => array(),
             'reference' => 'distref-as-no-source',
             'dev-requirement' => false,
@@ -41,6 +50,9 @@ return array(
         'a/provider2' => array(
             'pretty_version' => '1.2',
             'version' => '1.2.0.0',
+            'type' => 'library',
+            // @phpstan-ignore-next-line
+            'install_path' => $dir . DIRECTORY_SEPARATOR . '/foo/bar/vendor/woop/woop',
             'aliases' => array(
               '1.4',
             ),
@@ -50,6 +62,9 @@ return array(
         'b/replacer' => array(
             'pretty_version' => '2.2',
             'version' => '2.2.0.0',
+            'type' => 'library',
+            // @phpstan-ignore-next-line
+            'install_path' => $dir . DIRECTORY_SEPARATOR . '/foo/bar/vendor/woop/woop',
             'aliases' => array(),
             'reference' => null,
             'dev-requirement' => false,
@@ -57,6 +72,9 @@ return array(
         'c/c' => array(
             'pretty_version' => '3.0',
             'version' => '3.0.0.0',
+            'type' => 'library',
+            // @phpstan-ignore-next-line
+            'install_path' => $dir . DIRECTORY_SEPARATOR . '/foo/bar/vendor/woop/woop',
             'aliases' => array(),
             'reference' => null,
             'dev-requirement' => true,