QSMP3 is the first (AFIK) MP3 Player component that works on both Kylix and Delphi.
It is based on the JEDI-SDL translation of SMPEG (SDL MPEG Library), and SDL (Simple DirectMedia Layer), a cross-platform freeware multimedia library similar to DirectX. Windows versions of both of these libraries (.DLLs) are included with this package, and they come with most Linux distros. The JEDI-SDL headers are also included, and work with both OSes.
QSMP3 supports MP3 Playback, seeking, real-time & on-request position reporting, and volume control on BOTH Linux *AND* Windows.
This is v1.02 (RC1). It is still in development, but is very usable and stable. Event support is still incomplete, but the most important event, OnPositionChange (position-in-file reporting), is 100% complete.