If you're an API developer or an open-source enthusiast looking for a cost-effective solution, hoppscotch is your best choice. It's completely free, supports offline and on-premises usage, and works across multiple platforms. However, if you need a tool with extensive integrations or advanced features, hoppscotch may fall short.
On the other hand, if you're in the design field and prioritize privacy or are aligned with open-source principles, Penpot is an excellent option. It offers real-time collaboration and is built on open standards, making it great for design teams that include developers. Just be aware that you might miss out on the extensive plugin ecosystem and polish that tools like Figma provide. So, choose Penpot if you value open-source capabilities and real-time teamwork, but consider other options for a more robust design experience.