Processing. OpenProcessing - Share your sketches! Processing (programming language) Processing includes a sketchbook, a minimal alternative to an integrated development environment (IDE) for organizing projects. Every Processing sketch is actually a subclass of the PApplet Java class which implements most of the Processing language's features. When programming in Processing, all additional classes defined will be treated as inner classes when the code is translated into pure Java before compiling. This means that the use of static variables and methods in classes is prohibited unless you explicitly tell Processing that you want to code in pure Java mode.
Processing also allows for users to create their own classes within the PApplet sketch. This allows for complex data types that can include any number of arguments and avoids the limitations of solely using standard data types such as: int (integer), char (character), float (real number), and color (RGB, ARGB, hex). The Processing equivalent of a Hello World program is simply to draw a line:[1]
Processing 101. 00 - Processing 101 - Introduction. 05 - Processing 101 - Using Variables. Processing.org.