My info might be out of date, but I think for a long time Debian was not including some audio codecs like MP3 because there are some patents around it. I think

My info might be out of date, but I think for a long time Debian was not including some audio codecs like MP3 because there are some patents around it. I think there are some proprietary drivers like NVidia that are also excluded. I think the Debian distro has always targeted/attracted free software purists.