The free, open source, darktable image editor comes as a good alternative to Lightroom for Windows. And of course it runs on all linux and Mac platforms.
If you are looking for a free alternative to image management and editing such as Lightroom, there are some good news: free and open source software darktable has reached the 2.4.0 version and is finally available for Windows users as well.
The darktable originally released in 2009, it has been used by professional photographers on Mac and Linux operating systems. The software includes a set capabilities photo editor that helps you edit RAW files, especially large sizes.
After some timid attempts with version 2.2.0, darktable is now officially ported to Windows OS (only for 64-bit), in this new version of 2.4.0, and as its developers state in their announcement, they intend to support it in the future.
Although the Windows version of it is missing some features (for example, there is no print support), it has some limitations and comes with its own bugs (importing and exporting TIFF does not support non-ASCII characters in filenames) , overall we are sure that it is quite usable and we hope you will enjoy it.
In addition to Windows support, 2.4.0 brings a series of new changes, features, bug fixes, and camera support. You can find the entire list of changes and improvements to company announcement.