Sonic Visualiser is a free software system distributed under the GNU

GNU

GNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...

 General Public License which allows you to visualise, analyse and annotate sound files. It is used in musical as well as scientific work, its most outstanding feature is the ability to use highly specialised third-party plugins in the vamp plugin format . It was developed at the University of London

University of London

-20th century:Shortly after 6 Burlington Gardens was vacated, the University went through a period of rapid expansion. Bedford College, Royal Holloway and the London School of Economics all joined in 1900, Regent's Park College, which had affiliated in 1841 became an official divinity school of the...

's Centre for Digital Music and is compatible with Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, Mac OS/X, and Windows operating systems.