If you are in a need of professional photo editing software program , anybody would suggest you to go for Adobe Photoshop.  Even though it is one of the most popular imaging software, many people cannot afford to buy it because of the high cost.

However, if you do a research on the internet you can find a number of competitive imaging software with similar features like that of Photoshop and that too for free. These are known as Freeware or Open Source software. We have carefully studied, reviewed and listed top 15 Excellent Open Source Alternatives To Photoshop which are mostly recommended by web designers:

GIMP : GNU Image Manipulation Program is one of the most powerful and widely used substitutes for Adobe Photoshop. With this amazing easy to use software, you can create graphics and logos, change the size of the photos, combine different images, color balancing, crop photos, add effects to the images, convert different types of images, make animated GIF images, etc. You can easily work with this software on Microsoft Windows, Mac OS X and UNIX. You can work various types of image formats such as BMP, JPEG, PNG, GIF, TIFF and also on images that are created from Corel Paint Shop Pro and Adobe Photoshop.

Krita : It is the bitmap graphics editor software that comes built-in with KOffice, an office suite program like Microsoft Office. The interface of this software is very similar to Photoshop. You can do various photo editing work  such as  painting, add gradients, add colors and patterns, create brushes, change size, rotate, shear, mirror, edit between layers, etc. You can extend this software by adding various painting and editing plug-ins. Although it is a wonderful image editing software, pundits suggest using it for manipulating images rather than making new images on it. In the future, you can expect natural painting tools which will be able to reproduce the same effect as if you are drawing with pencil, painting, etc on a paper.

Paint.NET : Most people consider this wonderful photo editing program to be an improved version of the built-in program of Windows, Microsoft Paint. If you are looking for simple software to small image editing jobs, then this software is just the one for you. You can open several images at one time and work on them, work on different layers of the images, add effects to the image, history tool to check the modifications done on the image, etc. You can add more effects to the image by adding plug-ins to this software. This powerful software is supported by a superb online community from where you can seek help, learn more about imaging through tutorials and download more plug-ins.

ChocoFlop : ChocoFlop is a dedicated image editing software for MAC operating system computers. It is powered by Apple’s CoreImage technology to easily edit your photos. The program launches quickly and does not put pressure on the processor. You can do image creation, you can make use of layers and filters, do basic image editing work like re-sizing the image, cropping the image and convert images across different file formats. It gives users real-time previews of filters. You can work on all the popular image formats. Whatever editing or modifications you do to your image, you will not lose its quality.

CinePaint : Even though it is available for free, this image editing software can be used to work high-end image formats like Kodak Cineon and SMPTE DPX. This image editing software is mainly used for retouching image frames of motion pictures. It is one of the most famous software for working on motion films. This powerful paint manipulation and image processing software has been in used in a number of movies such as The Last Sumari, Dr.Dolittle 2, Stuart Little, Spider-man and Harry Potter and the Philosopher’s Stone. The Windows version of this software is under process but it can be used across various platforms such as Linux, Mac, Native and Unix.

Pixia : It is an photo editing software primarily meant for Microsoft Windows. Although it is Japanese software, it is available in various languages such as English, French, Italian, Chinese, Korean, German, etc. The interface is very easy to use; hence beginners and experts can work on it easily. All kinds of basic and standard image editing can be done on this software. You can create images, work on layers, masks, paint using different types of brushes, add effect to the images, etc. The only main drawback of this software is that you cannot work on GIF animated images and some well-known image formats.

Pixen : This graphic editor has been developed to work on MAC OS only. The interface of this application is very similar to that of Adobe Photoshop. You can efficiently work on different layers of the image, create and edit GIF animated images, a powerful color palette to edit and reuse images, assign a different tool such as pencil, eraser, brush, etc to the left and right buttons of the mouse. It allows you to arrange different parts of the image, give a name to them and you can also even hide them. Just like other well-known photo editing software, this software also has small dedicated windows for images, layers and tools. You can work on following image formats PXI, GIF, MOV, JPG, PNG, BMP, ICO, .PICT and many more.

Picnik : Make use of this amazing image editing program to edit your photos easily online through your Flash enabled web browser. You can simply upload an image on this website and start editing it in no time. You can import photos from some of the well-known websites such as Facebook, MySpace, Flickr, PhotoBucket, Picasa, Webshots, Webs, etc. You can fix, fine-tune, crop, resize, rotate, add effects, add texts, etc to your photos for free. It works easily on MAC, Windows and Linux computers and you do not even have to download or install anything to access its feature. By paying a reasonable annual subscription fee you can upgrade this application to access additional photo editing features.

Splashup : It is a web based application that allows you to edit your photos and manage them online through your web browser. Since it runs in Flash, your browser should have Flash installed on it. You can various kinds of jobs such as multiple image editing, pixel level controlling, work on different layers and filters, etc. You can easily integrate it with some of the popular photo sharing websites such as Picasa, Flickr and Facebook. If you want to work more on your photos, then you can download the free application called Splashup Light and modify your images by adding effects, adjust color depths, add texts, etc. JPEG, GIF and PNG are the supported image formats.

Adobe Photoshop Express : You can make use of this powerful web based application from Adobe to edit your photos online. You need to have Flash installed on your browser to make use of it. Without downloading any program you can edit your photos. You can do all the basic image editing such as add effects to your photos, crop and resize, sharpen, blur, rotate, touch up, etc on it easily. Once you register on the Adobe Photoshop Express website you can edit your photos, store them on a 2GB storage space and share them with your friends online through various blogs and social networking websites such as Facebook, Picasa and Photobucket with ease.

Ajax Image Editor : Formerly known as Akole, Ajax Image Editor is a very user-friendly online image editing and manipulation application. You can integrate this application easily to your web browser and make the most of the image editing. On their website you can find the live demo, which can be accessed to checkout the simulation of their image editing application.  You can resize, crop, rotate, add filters, watermark, add text, access all the recent modifications to the image by the history feature, etc. There is no plug-in needed, everything can be done on the website itself. The help option will guide in you perfectly editing your photos.

Sumo Paint : Yet another online photo editing application that can be used to create and edit images by making of use of its easy to use tools. The application can launches easily through your web browser and its interface is very much similar to that of Adobe Photoshop. You can do a lot with layers, give effects to the image, add shape tools, add brushes, make use of realistic inks for painting, add text, filters, gradient, gravity, etc. The features it boasts of is enough to rate it as a professional photo editing application. The application does not slow down your computer. The Support feature of this application is enough to teach a person with a limited knowledge about image editing to create and edit images professionally.

Pixlr : An online image editing application, Pixlr aims at provides its users an effortless experience towards creating and editing photos. The website can accessed through any Flash enabled website. If you are someone who would like to edit and upload your photos to blogs, social networking websites and photo sharing websites, then this application is simply one of the best ones to do the needful. Though it is a relative new website compared to its competitors, in a short span of time it has attracted significant volumes of traffic. This application lacks some vital features like redo, add text tool, crop tool and history tool.

Aviary : It is an online professional suite mainly developed in keeping mind for creative designers. It requires a Flash enabled web browser to make use of its powerful features. The suite includes several other dedicated applications for photo editing, visual laboratory, palette editor and to create and edit vector graphics. You can do all kinds of basic image editing work for free; however, you need to pay a monthly fee of $15 to access the Pro membership to access additional features, high-end tutorials, etc. The interface is very user-friendly and you can work on wide range of image formats. The forum and chat feature of Aviary makes it all the user-friendly.

Inkscape : It is powerful software that can be downloaded on to your Linux, Mac OS, Windows powered computers to make and edit vector graphic images. This software is very similar to other vector graphics image editors like Adobe Illustrator, CorelDraw, Xara X, etc. The site Inkscape.org has screenshots and tutorials to help you in using this application effectively. You can make various types of objects such as paths, rectangles, ellipses, polygons, clones, spirals, 3D boxes and text. You can also export PNG JPEG BMP file format images and work on it. It has multi language support. One of the major drawbacks of this application is that you cannot work on animated images.

Keep in mind that to access online image editing software you need to have a broadband internet connection to make the best use of it. A dial-up internet connection may fail to load the website. Anybody with limited photo editing knowledge can do standard to professional photo editing easily on the above mentioned Open Source Alternatives to Photoshop. Special thanks to Sixrevisions.com from where I got best information on professional photo editing software .