Raw Therapee

High Image Quality

96-bit (floating point) processing engine.
Non-destructive editing.
Get the most details and least artifacts from your raw photos thanks to modern and traditional demosaicing algorithms: AMaZE, DCB, AHD, EAHD, HPHD, IGV, LMMSE, VNG4, Mono and Fast.
Advanced color handling from white balance to HSV (Hue-Saturation-Value) curves, color toning and color management including wide-gamut and soft-proofing support.
Powerful CIE Color Appearance Model 2002 (CIECAM02) module.
Enhanced exposure and tonality tools: tone and Lab curves, highlights and shadows tools, tone mapping (HDR-like effect), etc.
Multiple denoising methods: luminance, chrominance (both rewritten in 2012), impulse (for salt and pepper noise) noise reduction.
Several tools to enhance details: unsharp mask, RL deconvolution, contrast by detail levels.

Efficiency

Multi-threaded algorithms for high performance (RawTherapee can utilize modern processor features, like SSE).
Quick thumbnails load lightning fast and are replaced later with live thumbnails.
Batch processing: convert all the developed images at once without loading the processor while you work.
Copy/paste editing parameters from one file to many other. Partially copying and/or pasting is also possible.
Basic tools immediately at your hands.
Parallel editing of multiple images in separate editor tabs, and/or all at once from the file browser.
An optional secondary display can be used.

Wide variety of supported cameras: almost all DSLRs and even some medium format bodies are supported.
Can load most raw files including 16-, 24- and 32-bit raw HDR DNG images, as well as standard JPEG, PNG (8- and 16-bit) and TIFF (8-, 16- and 32-bit logluv) images.
Can save JPEG, PNG (8- and 16-bit) and TIFF (8- and 16-bit) images.
Advanced control over the algorithms with many fine-tuning parameters and curves.
Can send to GIMP or the editing tool of your choice in one click (16-bit TIFF file).
Command line usage besides the normal graphical interface.
Various layouts: multiple tabs, single tab with filmstrip, vertical tab with filmstrip, dual monitor.

RawTherapee is free and open source software, meaning you can use it free of charge, wherever you like on whatever hardware you like, as long as you abide by the copyleft GPLv3 license. Download the source code, modify it, feel free to do what comes to mind. We believe in open software.
It is cross-platform - you can use it on Linux, macOS or Windows.
International: it is available in 25 languages!

http://goo.gl/K32aYg