Luckily, there are quite a few open source/free Photoshop Alternatives. Here’s my favourite 5:

1. Paint.Net

Once a replacement for Microsoft’s Paint application, Paint.Net has grown into fully fledged graphics editing suite. I enjoy using it because it is relatively easy to use.

2. Gimp

Probably the most popular Photoshop of the lot, Gimp has grown in features and user base since its release in 1995. I use this with Paint.Net – Mainly for some quick logo designs.

3. Krita

Krita is open source bitmap editing and drawing with the following advanced features: 16-bit image support, High dynamic resolution images, CMYK and even color management. As part of the KOffice suite it added a full features image editing and draw application – including lots of filters for either serious use or just to play around with.

Here is a tutorial on Krita (Using a tablet for drawing)

4. Fotografix

Fotografix has a ridiculously small footprint. It’s a 370Kb download and about 700Kb once extracted. Despite its size, most of the features I rely on in Photoshop are available. Another download link : Click Here

5. Picnik

Picnik is a web based photo editor that has recently taken off due to a partnership with Flickr. It has all the basic features plus a few advanced ones like layers and special effects. It is cross platform since you only need a browser.

Here is a tutorial: