Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/language/config/install/language.entity.en.yml

@@ -0,0 +1,7 @@
+id: en
+label: English
+direction: 'ltr'
+weight: 0
+locked: false
+status: true
+langcode: en

core/modules/language/config/install/language.entity.und.yml

@@ -0,0 +1,7 @@
+id: und
+label: 'Not specified'
+direction: 'ltr'
+weight: 1
+locked: true
+status: true
+langcode: en

core/modules/language/config/install/language.entity.zxx.yml

@@ -0,0 +1,7 @@
+id: zxx
+label: 'Not applicable'
+direction: 'ltr'
+weight: 2
+locked: true
+status: true
+langcode: en

core/modules/language/config/install/language.mappings.yml

@@ -0,0 +1,13 @@
+# Browsers use different language codes to refer to the same languages,
+# these defaults handles the most common cases.
+map:
+  no: 'nb' # Norwegian
+  pt: 'pt-pt' # Portuguese
+  zh: 'zh-hans' # Default Chinese to simplified script
+  zh-tw: 'zh-hant' # Taiwan Chinese in traditional script
+  zh-hk: 'zh-hant' # Hong Kong Chinese in traditional script
+  zh-mo: 'zh-hant' # Macao Chinese in traditional script
+  zh-cht: 'zh-hant' # traditional Chinese
+  zh-cn: 'zh-hans' # PRC Mainland Chinese in simplified script
+  zh-sg: 'zh-hans' # Singapore Chinese in simplified script
+  zh-chs: 'zh-hans' # simplified Chinese

core/modules/language/config/install/language.negotiation.yml

@@ -0,0 +1,9 @@
+session:
+  parameter: language
+url:
+  source: path_prefix
+  prefixes:
+    en: ''
+  domains:
+    en: ''
+selected_langcode: site_default

core/modules/language/config/install/language.types.yml

@@ -0,0 +1,17 @@
+all:
+  - language_interface
+  - language_content
+  - language_url
+configurable:
+  - language_interface
+negotiation:
+  language_content:
+    enabled:
+      language-interface: 0
+  language_url:
+    enabled:
+      language-url: 0
+      language-url-fallback: 1
+  language_interface:
+    enabled:
+      language-url: 0