1. Architecture: The key difference between CreateJS and three.js lies in their architecture. CreateJS is a suite of JavaScript libraries that provides tools for creating rich, interactive web content, including animations and games. It is built on top of HTML5 canvas and uses a hierarchical display tree structure for rendering. On the other hand, three.js is a lightweight 3D library for creating WebGL-based graphics and animations. It follows a scene-graph based architecture and provides a comprehensive set of features for rendering three-dimensional objects.

2. Rendering capabilities: CreateJS focuses primarily on 2D graphics and provides powerful tools for creating and manipulating vector-based graphics, animations, and interactive elements. It offers support for spritesheets, tweening, and physics simulations. In contrast, three.js is designed for 3D graphics and provides advanced features for rendering and manipulating three-dimensional objects, including lighting, shadows, and shaders. It offers support for complex geometric shapes, materials, and textures.

3. API design: CreateJS offers a high-level and intuitive API that abstracts many complexities of HTML5 canvas, making it easier for developers to create interactive content. It provides a simple and consistent interface for handling events, managing display objects, and animating elements. Three.js, on the other hand, has a more low-level API that exposes the full power of WebGL. It provides fine-grained control over rendering, shaders, and geometries, allowing developers to create highly customized 3D graphics.

4. Community and ecosystem: CreateJS has a large and active community of developers, with a wide range of resources and tutorials available. It also provides a visual authoring tool, Adobe Animate, that integrates well with CreateJS, making it easier to create animations and interactive content. Three.js also has a strong community and a rich ecosystem of plugins and extensions. It is widely used in the game development industry and has extensive documentation and examples.

5. Browser compatibility: CreateJS is designed to work across a wide range of browsers and devices, with support for older versions of Internet Explorer. It provides a fallback rendering mode using HTML5 canvas for devices that do not support WebGL. Three.js relies on WebGL for rendering, which is supported by most modern browsers. However, it may not work on older browsers or devices that do not support WebGL.

6. Performance: CreateJS is optimized for 2D graphics and animations, and it performs well for most interactive content. However, it may have limitations when it comes to rendering complex 3D scenes or handling large numbers of objects. Three.js, being a dedicated 3D library, is more efficient in rendering complex 3D scenes and can handle a large number of objects while maintaining good performance.

In summary, CreateJS is a comprehensive suite of JavaScript libraries for creating 2D graphics and animations, offering an intuitive API and wide compatibility, while three.js is a lightweight 3D library specifically designed for creating advanced 3D graphics and animations using WebGL, providing fine-grained control and optimal performance.