11 classes are annotated with CKEditorPlugin

DrupalImage in core/modules/ckeditor/src/Plugin/CKEditorPlugin/DrupalImage.php
Defines the "drupalimage" plugin.
DrupalImageCaption in core/modules/ckeditor/src/Plugin/CKEditorPlugin/DrupalImageCaption.php
Defines the "drupalimagecaption" plugin.
DrupalLink in core/modules/ckeditor/src/Plugin/CKEditorPlugin/DrupalLink.php
Defines the "drupallink" plugin.
Internal in core/modules/ckeditor/src/Plugin/CKEditorPlugin/Internal.php
Defines the "internal" plugin (i.e. core plugins part of our CKEditor build).
Language in core/modules/ckeditor/src/Plugin/CKEditorPlugin/Language.php
Defines the "language" plugin.
Llama in core/modules/ckeditor/tests/modules/src/Plugin/CKEditorPlugin/Llama.php
Defines the "Llama" plugin, with a CKEditor "llama" feature.
LlamaButton in core/modules/ckeditor/tests/modules/src/Plugin/CKEditorPlugin/LlamaButton.php
Defines a "LlamaButton" plugin, with a toolbar builder-enabled "llama" feature.
LlamaContextual in core/modules/ckeditor/tests/modules/src/Plugin/CKEditorPlugin/LlamaContextual.php
Defines a "Llama" plugin, with a contextually enabled "llama" feature.
LlamaContextualAndButton in core/modules/ckeditor/tests/modules/src/Plugin/CKEditorPlugin/LlamaContextualAndButton.php
Defines a "LlamaContextualAndButton" plugin, with a contextually OR toolbar builder-enabled "llama" feature.
LlamaCss in core/modules/ckeditor/tests/modules/src/Plugin/CKEditorPlugin/LlamaCss.php
Defines a "LlamaCss" plugin, with an associated "llama" CSS.
StylesCombo in core/modules/ckeditor/src/Plugin/CKEditorPlugin/StylesCombo.php
Defines the "stylescombo" plugin.

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.