Seashore is an open source image editor for Mac OS X's Cocoa framework. It features gradients, textures and anti-aliasing for both text and brush strokes. It supports multiple layers and alpha channel editing. It is based around the GIMP's technology and uses the same native file format.

However, unlike the GIMP, Seashore only aims to serve the basic image editing needs of most computer users, not to provide a replacement for professional image editing products.

Seashore's features include:

• Full support for the GIMP's native XCF file format
  
• Read and write support for the TIFF, PNG, JPEG, JP2000 and GIF file formats
  
• Read-only support for the BMP, PICT, PDF and XBM file formats
  
• Layers with over 20 merging effects
  
• Ability to edit just the primary or alpha channels
  
• Thorough transparency effects including semi-transparent gradients
  
• Arbitrary selection regions
  
• Anti-aliased brush strokes
  
• 6 basic gradient effects with 16 variations
  
• Tablet support
  
• ColorSync support (including embedded profiles in TIFFs and CMYK previewing)
  
• Plug-in filters