For API development, choose Hoppscotch if you're an API developer or an open-source enthusiast looking for a free and straightforward tool that supports offline usage and can be deployed on-premises. It's perfect for individuals or small teams that do not require extensive third-party integrations or advanced features typical of paid solutions. However, if you seek a comprehensive suite with advanced capabilities and numerous integrations, this isn't the right choice.
On the other hand, if you're focused on design and prototyping, particularly in a collaborative environment, Penpot is ideal for open-source advocates and privacy-conscious teams. It offers real-time collaboration and is built for seamless interaction between designers and developers. If you can manage with a smaller ecosystem and slightly less polished performance compared to competitors like Figma, Penpot will serve you well. Avoid it if you need the vast plugin ecosystem and refinement that comes with mainstream design tools.