Developer Robbie Tilton released Compositor, an open-source image editor for Mac built as a free alternative to Adobe Photoshop, according to its GitHub repository. The MIT-licensed project has drawn more than 5,600 stars and 600 forks since it was created earlier this month.
Tilton built the app to close what he calls a gap between paid tools and free ones: "Adobe Photoshop costs too much and tools like GIMP don't feel familiar enough," according to the repository. Compositor mirrors Photoshop's conventions, including its keyboard shortcuts and drag-to-scrub value adjustments.
The app supports layer folders, opacity and blend modes, layer masks, clipping masks and adjustment layers, along with non-destructive transform tools, multiple selection types, content-aware fill and Camera Raw processing, according to the repository. It imports and exports JPEG, PNG, HEIC, TIFF, SVG, RAW and Photoshop's native PSD and PSB formats.
Compositor also exposes its projects to direct editing by AI agents and scripts, according to the repository. It requires macOS 26.5 or later, is built with Swift, and ships through direct download, GitHub Releases or Homebrew, with code signing and notarization.
A Photoshop-compatible editor that agents can script directly is a bet that image editing is headed where coding already went: a human and an agent working the same file. Whether Compositor can keep pace with Adobe's feature set past its first weeks of hype is the real test.