Pencil is an open-source GUI prototyping tool that's available for ALL platforms. Pencil is built for the purpose of providing a free and open-source GUI prototyping tool. Developed by Pascal Naidon and Patrick Corrieri
License: Open Source
Pencil is an intuitive sketching tool ideal for quick illustrations and collaborative projects, while Karbon offers advanced vector editing and design capabilities suited for professional UI/UX work. The choice between them depends on the user's specific needs—whether for casual drawing or more complex design tasks.