ember-sortable is an Ember.js addon providing sortable UI primitives for drag-and-drop reordering of lists, grids, and tables. It implements modifiers (sortable-group, sortable-item, sortable-handle) that attach drag-and-drop behavior to DOM elements, with built-in support for mouse, touch, and keyboard input. The architecture centers around a service (ember-sortable-internal-state) that manages state between sortable groups and items, enabling features like visual feedback during drag, automatic container scrolling, and accessibility support including screen reader announcements and keyboard navigation. The library follows Ember addon conventions with a modular structure, clear separation of concerns, and comprehensive test coverage.

Ember Data Factory Guy is an Ember.js addon designed for factory-based testing in Ember Data applications. It replaces traditional fixtures with factory definitions to generate test data, providing methods like `make`, `build`, and `mock*` for creating and persisting test records. The addon includes request mocking capabilities supporting both Pretender and MSW libraries, scenario management for test setup, and serializer-specific builders/converters for JSONAPI, REST, JSON, and ActiveModel formats. Architecture follows Ember addon conventions with a clear separation between core factory logic, adapter-specific handling, and mocking abstraters. The test application demonstrates usage patterns but is not the primary product.