Compositor

Compositor is a free, open-source image editor for macOS designed around professional compositing and post-processing workflows. It provides Photoshop-style layers, folders, opacity controls, blend modes, masks, clipping masks, and adjustment layers. Non-destructive transformations allow images to be moved, scaled, rotated, flipped, or distorted while preserving source resolution. Built-in adjustments and effects include curves, levels, exposure, color controls, blur, noise, shadows, glows, and overlays. Multiple projects can be opened in tabs, and layers can be copied or moved between documents. The application supports common image formats and includes crop, resize, export, color-picking, and custom drawing workflows. Its source can be built and modified through Xcode.