At a fraction of the size, and incomparable in cost, since it’s available for FRE, Artweaver is a pretty good alternative to a very expensive piece of software. It supports most of the features Photoshop does, like layers, plugins, brushes, a few effects and even tablet support. !t is currently in version 0.5 and is available in English and German but since it has an SDK other languages and plugins can easily be developed and added by other developers.
You can see the list of available features and download the application (8.8MB) to try out for yourself – no complicated installation, just download, extract and try it out. If you’ve used Photoshop before you’ll feel right at home.