Pencil Project is an open-source GUI prototyping tool. Developed by Evolus
License: Open Source
Axure RP is a powerful tool designed for creating high-fidelity, interactive prototypes with advanced collaboration features, making it ideal for professional designers. In contrast, Pencil Project is an open-source, user-friendly tool that excels in low-fidelity wireframing, making it suitable for quick mockups and designs.