diff --git a/pkgs/yaml/LICENSE b/pkgs/yaml/LICENSE
index 162572a..e7589cb 100644
--- a/pkgs/yaml/LICENSE
+++ b/pkgs/yaml/LICENSE
@@ -1,27 +1,20 @@
-Copyright 2014, the Dart project authors.
+Copyright (c) 2014, the Dart project authors.
+Copyright (c) 2006, Kirill Simonov.
 
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
 
-    * Redistributions of source code must retain the above copyright
-      notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above
-      copyright notice, this list of conditions and the following
-      disclaimer in the documentation and/or other materials provided
-      with the distribution.
-    * Neither the name of Google LLC nor the names of its
-      contributors may be used to endorse or promote products derived
-      from this software without specific prior written permission.
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
 
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/pkgs/yaml/benchmark/benchmark.dart b/pkgs/yaml/benchmark/benchmark.dart
index f5dc9e7..adde6f8 100644
--- a/pkgs/yaml/benchmark/benchmark.dart
+++ b/pkgs/yaml/benchmark/benchmark.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2015, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 library yaml.benchmark.benchmark;
 
diff --git a/pkgs/yaml/example/example.dart b/pkgs/yaml/example/example.dart
index 102d5b1..672ead9 100644
--- a/pkgs/yaml/example/example.dart
+++ b/pkgs/yaml/example/example.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2020, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:yaml/yaml.dart';
 
diff --git a/pkgs/yaml/lib/src/charcodes.dart b/pkgs/yaml/lib/src/charcodes.dart
index 705da62..602d597 100644
--- a/pkgs/yaml/lib/src/charcodes.dart
+++ b/pkgs/yaml/lib/src/charcodes.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2021, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 /// Character `+`.
 const int $plus = 0x2b;
diff --git a/pkgs/yaml/lib/src/equality.dart b/pkgs/yaml/lib/src/equality.dart
index b232eb9..edaef89 100644
--- a/pkgs/yaml/lib/src/equality.dart
+++ b/pkgs/yaml/lib/src/equality.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'dart:collection';
 
diff --git a/pkgs/yaml/lib/src/error_listener.dart b/pkgs/yaml/lib/src/error_listener.dart
index dac7d63..a0a0d95 100644
--- a/pkgs/yaml/lib/src/error_listener.dart
+++ b/pkgs/yaml/lib/src/error_listener.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2021, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'yaml_exception.dart';
 
diff --git a/pkgs/yaml/lib/src/event.dart b/pkgs/yaml/lib/src/event.dart
index e8879ee..0cf19cd 100644
--- a/pkgs/yaml/lib/src/event.dart
+++ b/pkgs/yaml/lib/src/event.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 
diff --git a/pkgs/yaml/lib/src/loader.dart b/pkgs/yaml/lib/src/loader.dart
index 07f5c8b..4ec6017 100644
--- a/pkgs/yaml/lib/src/loader.dart
+++ b/pkgs/yaml/lib/src/loader.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 import 'package:yaml/src/error_listener.dart';
diff --git a/pkgs/yaml/lib/src/null_span.dart b/pkgs/yaml/lib/src/null_span.dart
index 64b3551..badb495 100644
--- a/pkgs/yaml/lib/src/null_span.dart
+++ b/pkgs/yaml/lib/src/null_span.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 
diff --git a/pkgs/yaml/lib/src/parser.dart b/pkgs/yaml/lib/src/parser.dart
index aeeda4e..8a559c8 100644
--- a/pkgs/yaml/lib/src/parser.dart
+++ b/pkgs/yaml/lib/src/parser.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 import 'package:string_scanner/string_scanner.dart';
diff --git a/pkgs/yaml/lib/src/scanner.dart b/pkgs/yaml/lib/src/scanner.dart
index fdf9277..fcf6d27 100644
--- a/pkgs/yaml/lib/src/scanner.dart
+++ b/pkgs/yaml/lib/src/scanner.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:collection/collection.dart';
 import 'package:source_span/source_span.dart';
diff --git a/pkgs/yaml/lib/src/style.dart b/pkgs/yaml/lib/src/style.dart
index 6ddaf3d..e3415d8 100644
--- a/pkgs/yaml/lib/src/style.dart
+++ b/pkgs/yaml/lib/src/style.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 /// An enum of source scalar styles.
 class ScalarStyle {
diff --git a/pkgs/yaml/lib/src/token.dart b/pkgs/yaml/lib/src/token.dart
index 711950c..282d773 100644
--- a/pkgs/yaml/lib/src/token.dart
+++ b/pkgs/yaml/lib/src/token.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 
diff --git a/pkgs/yaml/lib/src/utils.dart b/pkgs/yaml/lib/src/utils.dart
index 2c69ead..66ef3ed 100644
--- a/pkgs/yaml/lib/src/utils.dart
+++ b/pkgs/yaml/lib/src/utils.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2013, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 
diff --git a/pkgs/yaml/lib/src/yaml_document.dart b/pkgs/yaml/lib/src/yaml_document.dart
index 65b9548..da6aa1e 100644
--- a/pkgs/yaml/lib/src/yaml_document.dart
+++ b/pkgs/yaml/lib/src/yaml_document.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'dart:collection';
 
diff --git a/pkgs/yaml/lib/src/yaml_exception.dart b/pkgs/yaml/lib/src/yaml_exception.dart
index 1941f02..1e6fb2e 100644
--- a/pkgs/yaml/lib/src/yaml_exception.dart
+++ b/pkgs/yaml/lib/src/yaml_exception.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2013, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 
diff --git a/pkgs/yaml/lib/src/yaml_node.dart b/pkgs/yaml/lib/src/yaml_node.dart
index 3e3ae8d..02c8439 100644
--- a/pkgs/yaml/lib/src/yaml_node.dart
+++ b/pkgs/yaml/lib/src/yaml_node.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2012, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'dart:collection' as collection;
 
diff --git a/pkgs/yaml/lib/src/yaml_node_wrapper.dart b/pkgs/yaml/lib/src/yaml_node_wrapper.dart
index 87328ba..fa6923d 100644
--- a/pkgs/yaml/lib/src/yaml_node_wrapper.dart
+++ b/pkgs/yaml/lib/src/yaml_node_wrapper.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'dart:collection';
 
diff --git a/pkgs/yaml/lib/yaml.dart b/pkgs/yaml/lib/yaml.dart
index d150725..5c1e729 100644
--- a/pkgs/yaml/lib/yaml.dart
+++ b/pkgs/yaml/lib/yaml.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2012, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'src/error_listener.dart';
 import 'src/loader.dart';
diff --git a/pkgs/yaml/libyaml-license.txt b/pkgs/yaml/libyaml-license.txt
deleted file mode 100644
index 050ced2..0000000
--- a/pkgs/yaml/libyaml-license.txt
+++ /dev/null
@@ -1,19 +0,0 @@
-Copyright (c) 2006 Kirill Simonov
-
-Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (the "Software"), to deal in
-the Software without restriction, including without limitation the rights to
-use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-of the Software, and to permit persons to whom the Software is furnished to do
-so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
diff --git a/pkgs/yaml/test/span_test.dart b/pkgs/yaml/test/span_test.dart
index b8170e6..03b7f9c 100644
--- a/pkgs/yaml/test/span_test.dart
+++ b/pkgs/yaml/test/span_test.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2019, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'dart:convert';
 
diff --git a/pkgs/yaml/test/utils.dart b/pkgs/yaml/test/utils.dart
index f90ac5b..0aeaea5 100644
--- a/pkgs/yaml/test/utils.dart
+++ b/pkgs/yaml/test/utils.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2014, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:test/test.dart';
 import 'package:yaml/src/equality.dart' as equality;
diff --git a/pkgs/yaml/test/yaml_node_wrapper_test.dart b/pkgs/yaml/test/yaml_node_wrapper_test.dart
index e5d71cc..a64ab58 100644
--- a/pkgs/yaml/test/yaml_node_wrapper_test.dart
+++ b/pkgs/yaml/test/yaml_node_wrapper_test.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2012, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:source_span/source_span.dart';
 import 'package:test/test.dart';
diff --git a/pkgs/yaml/test/yaml_test.dart b/pkgs/yaml/test/yaml_test.dart
index dffb9d5..a0cb553 100644
--- a/pkgs/yaml/test/yaml_test.dart
+++ b/pkgs/yaml/test/yaml_test.dart
@@ -1,6 +1,9 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
+// Copyright (c) 2012, the Dart project authors.
+// Copyright (c) 2006, Kirill Simonov.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
 
 import 'package:test/test.dart';
 import 'package:yaml/src/error_listener.dart';