GIMP

It's the best free alternative to Adobe Photoshop

The multi-window interface is better than single-window :)

I used it only once and not for a long time, but In comparison with windows paint , i found it more flexible, powerful and fun, specially i like the air bruch in Gimp very much.

I wouldn't want any other! I don't only love the feature richness but also the interface with its rightclick menu and the single windows. [3]

Waiting for the one window mode supposedly coming in the next release.

I wouldn't want any other! I don't only love the feature richness but also the interface with its rightclick menu and the single windows. [2]

Probably the best free photo editing program out there. IT still has its problems, but it is still a lot better than MS paint.

I wouldn't want any other! I don't only love the feature richness but also the interface with its rightclick menu and the single windows.

no photoshop?

Удобный и бесплатный редактор для разных платформ.

If you are a Photoshop freak, you are not going to be so happy with the little Gimper. It isn't set up even remotely anything like you are used to, and it uses multiple pallets to do it. Make yourself use it, the same way you made yourself learn to use the console! (Obviously I am speaking from a Linux point of view here) I like to look at it this way;
A number 2 pencil can make the most beautiful pieces of art known to mankind, and the most expensive art kit in the world in untrained hands is 100% useless. Give the Gimp a chance, you will not be sorry!

Easier to use then Adobe PS

Very good but has a step learning curve comparing to PS

A flexible image editor with no proprietary strings attached. The interface isn't terrible any more, but it's very odd because people are accustomed to Photoshop.

GIMP, an open source photo editor, is amongst the most well-known freeware programs. It's the Photoshop for the open source community - a good all-around tool for painting and image editing.

It does not leave a very good first impression though. The primary reason why GIMP is called a pile of rubbish and quickly uninstalled is it's user interface. Older versions of GIMP had a multi-window interface where EVERYTHING had it's own window - the tools, layers, your image (god forbid if you had several images!), colour picker etc. A very cluttered interface was created. Imagine having such a mess on your desktop - http://www.async.com.br/~kiko/pygtk-web/img/gimp-screenshot.png
The newer versions have a bit more more "intact" user interface but the docks still float and that is hands down my biggest complaint. It's annoying when you switch to you web browser for a second and then look at GIMP only to discover that your layers dock is buried below your image. Or when you constantly need to move the tools dock because it keeps covering up parts of your image. Rumors are about of a single-window interface being added in the next version, but that's still months away.

The upside is that GIMP has a highly customizable user interface. You can toss tabs around like ragdolls, tear away docks and delete whatever you don't want with the exception of the basic tools. This allows you to fine-tune the UI to accommodate your needs.

GIMP has a fairly standard toolset for a photo manipulator. A variety of selection tools, brush, clone, erase, paint bucket, transformation tools, dodge/burn. Transformation tools are sadly divided into scale, shear, flip, perspective and rotate. Why they couldn't have joined the tools is beyond me. But the weakest link in GIMP's toolset is most definitely it's abysmal text tool - writing creates a pop-up input window that you need to type your text in. In order to change the colour/size/etc of your text, you need be juggling between three windows, two of which have a habit of getting buried under the main window. It hard to put in words the frustration that you will feel when you try to make an image with large amounts of text in it.
Also, GIMP doesn't support layer groups which will you'll be missing when you have several dozen layers.

I now I've been ranting on a pretty negative tone here but....I'd be lying if I said that I consider GIMP to be a bad program. But in the mean time I can't really bring up anything extraordinarily good about the program. GIMP does not sit on a shaky throne built of "meh" and supported by a few awesome features. What makes it great is the things you barely notice. Those handy handles that can modify your selection. Script-Fu plugins. Exact modifications for selections.
GIMP does not glimmer or shine, but it's better than all the glitter-covered fakers.

It's important to note that GIMP is not a professional program so comparing it to the industrial standard (you all know what I'm talking about) is somewhat unfair. GIMP does not support CMYK, doesn't have 16-bit colour channel support, HDR nor does it have RAW support. If you think that you'll miss them, you are out of luck and should start thinking of a way to shell out the money for Photoshop. If you got no idea what these things are, you most likely won't need them and will find GIMP to be more than enough for your needs.

As any open-source program, GIMP is constantly being developed, extended and improved. If you took a look at GIMP some time ago and didn't like it, try giving it another shot - maybe your annoyances have been fixed.
Next versions of GIMP will most likely invalidate many of my complaints. For example, GIMP 2.8 will bring a new text tool that no longer uses a pop-up window for text editing and it also is rumored to have a single-window interface which would definitely improve the usability of the program.