This is your illustrator alternative! Fun, and we already see a good chunk of folks using this to prepare files for the laser out in the wild.
This is free photoshop with the worst multiwindow interface you ever done seen. People have fixed it so it functions 1to1 as PS does. Behind the stock interface it runs pretty darn well.
Want to transform it into PS proper? http://www.linuxandubuntu.com/home/how-to-transform-gimp-into-photoshop
This is a drawing program similar to Photoshop with limited text capabilities. The interface can be a little difficult to get used to since it's very different from most professional drawing programs, but is super useful for folks that have trouble transitioning from drawing by hand to digital as it closely mimics real life materials.
The program allows you to edit, create, and export as .PSD files, and is available on desktop, mobile, and tablets.
ALSO the full version is completely free to everyone now!
This is all about digital painting. Great for it, in fact.
https://krita.org/en/download/krita-desktop/
Get publishing with open source!