I have been working on moving from Windows to Linux for some time. I have been able to substitute most of my commercial apps with Open Source of Free ones. But since I go back and forth between Windows and Ubuntu I try to use the same apps on both systems. Recently David Revoy has posted a lot of info on his site in regards to Gimp-Painter and GPS (Gimp Paint Studio) that patched Gimp to emulate Corel Painter.
Needless to say I am a Windows user and know it pretty well, but I am in the process of learning Linux. Lucky enough there are people like David that will share the command lines that you can usually paste in Linux terminal windows which is similar to Windows cmd function.
Two other things I did not cover originally are the "Resynthesizer" and "Ora" plugin.
1 -The Resynthesizer plugin is akin to Photoshops "Content Aware" tool which is great for removing unwanted elements from an image by blending from the surrounding areas. It can be installed in Ubuntu 11.04 from the Ubuntu Software Center.
2-The Ora plugin allows you to save and read images with the .ora file extension. This is primarily used with MyPaint for layered images. It can be found here and copied into your plugin folder. Then right click it, go to permissions and allow it to be executable.
3-Here is a link to very good "How-to" on loading GIMP-Painter, Alchemy, and MyPaint on Windows. They also included a mega-file with all of the needed files, plugins, etc. It will make things easier to download them from one source.
Below is the code that David posted and the steps that finally worked for me.
This was done on Ubuntu 11.04:
1-make sure GIMP is not installed
2- Open up a Terminal Window and copy and paste the following.
sudo apt-add-repository ppa:mizuno-as/ppa && sudo apt-get update
sudo apt-get install gimp
unzip GPS\ 1_5_final\ release.zip -d ~/.gimp-2.6
rm GPS\ 1_5_final\ release.zip
3-Then go to the Ubuntu Software Center (Application Ubuntu Software Center) and install Gimp.
4-Verify that Gimp as been patched with Gimp-Painter by running GIMP and going to "Help>About" and seeing that under the GIMP title states gimp-painter as it does in the screen shot.
Let me know if it works for you.