foobar2000 is a modular, extensible audio player, designed to couple high quality playback and good usability with a very low disk and memory footprint. Some people would call it minimalistic, but this is not correct given the large amount of features and supported formats. I would rather call it...non-bloated.
I wrote several DSP components, which are now included by default in the program. On this page you can find some datafiles for them.