sk1project.net/

sK1 2.0 is professional quality illustration program for Windows, GNU/Linux and macOS platforms. sK1 2.0 is a powerful and mature application that makes users more productive and provides them professional and free solution even for exotic *nix OSes. Whether you are a newbie user or an experienced designer, sK1 2.0 makes it easy to get started. With its professional color-management engine and wide-range file format compatibility, sK1 2.0 provides color accuracy and drawing flexibility you need for all types of projects.