Free • Open Source. Krita is a professional Free and open source (FOSS) painting program. It is made by artists that want to see affordable art tools for everyone withith concept art, texture and matte painters, illustrations and comics. Very advanced program that is absolutely free, only downside is that it's not as lightweight as SAI. It has animation features, fullscreen support, and works well. Too glitchy and too hard to use. It will zoom in and out randomly making it hard to draw. It has many capabilities, and I've seen people's work using this. It's amazing to work in and is good in animation features. I realy like krita, it's a good alternative for paint tool sai even on windows, recomended! I have an older version of Krita, and I love it! It offers more brushes and options than most programs but it can be overwhelming at first. I totally recommend it. But I'm so accustomed to it that the newer one is hard to figure out. It's closer to photoshop than paint tool sai. lacks a lot of fuctions and runs really bad even on a mid high end pc. Let’s be clear, Easy Paint Tool SAI is unique software. Digital arts students use computers and other peripherals such as tablets to create art. They sometimes additionally work in digital photography, animation, electronic sound and music, graphic design, and other digital or interactive media. Popular programs such as Adobe® Photoshop® or Systemax Paint Tool SAI are often utilized together to allow artists to maximize their creativity.