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 a user-friendly drawing tool primarily aimed at raster graphics and animation, making it suitable for beginners and casual users. In contrast, Vectorian Giotto excels in vector graphics, offering precision and professional-grade features for graphic designers but has a steeper learning curve and higher resource demands.