Linux Softwares to Skinnable

Nightingale is a highly customizable cross-platform audio player with a focus on extensibility, featuring a beautiful interface, a wide array of supported formats, and tools like media library management, podcast playback, and integrated web browsing.

Audacious is a highly customizable, lightweight audio player designed for discerning listeners who prioritize sound quality and system resource efficiency. Supporting a vast array of audio formats and extensible via a robust plugin system, it offers a classic, skinnable interface for a personalized listening experience.

Launchy is a discontinued yet highly efficient open-source keystroke application launcher for Windows, macOS, and Linux. It allows users to quickly open programs, documents, and perform searches by typing their names, significantly speeding up workflow.