Fotoxx is a free open source Linux program for photo editing and collection management. The goal is to meet most user needs while remaining fast and easy to use.
With Fotoxx you can Navigate a large image collection using a thumbnail browser. Import camera RAW files and edit with 16-bit color. Save edited images as TIFF-8/16, PNG or JPEG with adjustable compression. Edit the whole image or a selected area, with adjustable edge-blending. Edit functions have live feedback using the full window. Undo/redo up to 99 edits. Add tags, dates, and star-ratings to images and search using these criteria and (wildcard) file names. Fotoxx does not use filters, layers, and masks - the edit functions work directly on the image.
The Panorama mode, for example, combines several shots, using a bit of manual placement from the user. Shots are placed one by one, and the results are pretty good – it isn't a replacement for stitching software, which creates a whole montage, but it does the job for a 360° panorama.
What Fotoxx calls HDF mode is a similar combination effect, but here it takes multiple images with different areas in focus, and tries to combine them into a continuous whole, giving an infinite depth of field.
There are plenty of other tricks, such as manual tone-mapping and HDR support. Again, this has the possibility for manual adjustment, so there's no problem taking separate images by hand rather than having a camera that takes three at once.
With support for a variety of RAW formats through the UFRaw libraries and 16-bit colour depth, Fotoxx can churn out high-quality images, given the right source material. There's basic tagging support using Exif data, but this is decentralised.
Some may argue this is a better way to organise images – Fotoxx stores your tags and other info direct to the Exif. The downside is that it has to index all the images if you're searching for a particular pic, which means knowing roughly where it is to begin with.
User Guide
Download Fotoxx DEB and RPM packages off here