Apps to Curve Manipulation

UFRaw (Unidentified Flying Raw) is a powerful and flexible open-source application designed for processing and manipulating raw image files from digital cameras. It provides a comprehensive suite of tools for non-destructive editing, batch processing, and conversion.

LightZone is a potent, open-source digital photo editor specifically designed for photographers. It offers unique tools for tone and color adjustments, non-destructive editing, and robust RAW file processing, making it a sophisticated alternative to mainstream photo editing software.

Darktable is a powerful, open-source and free photography workflow application and raw developer, offering professional-grade tools for managing and editing digital negatives. It's a non-destructive editor designed by photographers for photographers.

RawTherapee is a powerful, cross-platform open-source raw image processing application. It provides a comprehensive suite of tools for non-destructive editing of raw photographic files, offering advanced control over exposure, color, detail, and more for photographers seeking fine-tuned image manipulation without the limitations of compressed formats.

Photivo is a free and open-source photo processor designed for advanced users. It supports a wide range of RAW and bitmap file formats, offering sophisticated tools for image processing, editing, and conversion.

Inkscape is a powerful, free, and open-source vector graphics editor widely used for creating scalable vector graphics (SVG). It's suitable for a range of design tasks, from illustrations and logos to web graphics and PDF editing, offering a robust set of tools comparable to commercial software.