My Favorite FOSS Tools: pdfunite (poppler)pdfunite is a command line utility which is part of the PDF rendering library "Poppler".
My Favorite FOSS Tools: JustJust is a handy way to save and run project-specific commands. It is available for Linux, MacOS and Windows without additional dependencies.
My Favorite FOSS Tools: PintaPinta is my choice for a lightweight drawing tool. It is a Drawing/editing program modeled after Paint.NET. Its goal is to provide a simplified alternative to GIMP for casual users. Think of it like ms paint, but for all of us.
My Favorite FOSS Tools: Fish ShellFish is a user-friendly command line shell for Linux and macOS. It has tab completions, syntax highlighting and scripting was never that easy.