If you're a privacy-conscious team or an open-source advocate needing a design and prototyping tool, go for Penpot. It's genuinely open-source, self-hostable, and promotes real-time collaboration, making it suitable for teams that prioritize teamwork and open standards. However, if you're looking for a slick user experience and extensive plugin options, Penpot may fall short against Figma.
On the other hand, if you're a Mac user who values keyboard-driven workflows, Rectangle is your go-to choice. It's lightweight, free, and requires no accounts or telemetry, offering an effortless way to manage window layouts. However, if you're on a non-Mac platform or need an all-in-one utility suite for more comprehensive functionalities, Rectangle won’t meet your needs. Choose based on your specific environment and priorities.