Patternodes is a tool for creating graphical patterns, animations or illustrations based on repetitions. This is done by defining a sequence of steps, a recipe or sorts, that describes the pattern. Each pattern element or operation is represented by a little panel called a node, and the nodes are then linked by connections drawn between them. As the nodes can be freely combined and connected this gives you a very flexible and powerful interface.
While this interface requires a different way of thinking, it also offers a lot of benefits compared to traditional Illustrator-type editors. Most importantly it enables you to use sliders to instantly change any aspect, like color, spacing, scaling, rotation or repetition count of any part of the pattern without having to undo/redo any steps. In a sense you could say that PatterNodes is to graphic design what a parametric CAD-system is to product design.
Patternodes is designed from the start to make it easy to tweak things to see how they turn out. Therefore the resulting pattern tile is always shown in the bottom preview view, repeated and updating in real time with any changes, giving you instant feedback of what the end result will be.
While the software can be used to create any type of repeating graphic, it is primarily aimed at pattern creation. To make pattern creation easier Patternodes also includes a lot of nodes that automatically perform common tedious tasks like repeating elements at the tile edges to make the pattern seamless, or randomizing different aspects (like color, position, rotation..) of the elements in a pattern to give it a little more life.
Finally, when you are done you can simply copy the pattern tile into whatever illustration or graphics application you use, or export it either as vector graphics or a bitmap image file.