TCMixer is an X11 mixer with a neat interface. It uses X11 and Xpm libraries and does not require a bloated GUI toolkit to compile. Common audio controls are supported. It's very small, and takes up little desktop space.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.