From Gentoo Wiki
[ Results for search key : listen ] [ Applications found : 2 ] * dev-tinyos/listen [ Masked ] Latest version available: 1.1.15 Latest version installed: [ Not Installed ] Size of files: 10,032 kB Homepage: http://www.tinyos.net/ Description: Raw listen for TinyOS License: BSD * media-sound/listen [ Masked ] Latest version available: 0.6.3 Latest version installed: [ Not Installed ] Size of files: 859 kB Homepage: http://www.listen-project.org Description: A Music player and management for GNOME License: GPL-2 !!! The short ebuild name "listen" is ambiguous. Please specify !!! one of the above fully-qualified ebuild names instead.