Open Source MP3 Software
From the bowels of the open source dens of sourceforge.net comes the LAME project a open sourced MP3 encoder under a GPL license. Free to use and to modify if you happen to like tinkering with code, it started life way back 1998 when it MP2’s were the norm. Last updated March of last year, it may seem old but for audio enthusiasts who want free, user-changeable software then this is for you.
It is considered to be high quality encoding software but other software can compare. Other open sourced encoders have been left in the dust and may have ended their life a long time ago but this continues to thrive, somewhat. Very basic and straightforward, though a decent user-interface may be in order to get more users onto the bandwagon.