Nicola Bernardini's Csound site at AIMI. The most recent versions should always be available here and at the MusTec site: http://AIMI.dist.unige.it/AIMICSOUND/AIMICSOUND_home.html.
FTP server for the Music Technology Department at Bowling Green State University. Many Linux sound applications are available from this site: ftp://mustec.bgsu.edu/pub/linux/.
Not just for Linux Csounders, my own page includes pointers to orc/sco collections, on-line tutorials, web interfaces, sites with RealAudio clips and other good stuff: http://www.bright.net/~dlphilp/linux_csound.html.
Home of the canonical sources, maintained by John Fitch: ftp://ftp.maths.bath.ac.uk/pub/dream/.
My collection of links to everything MIDI and audio for Linux: http://www.bright.net/~dlphilp/linux_soundapps.html.
Information on joining the Csound UNIX/Linux Development mail-list, also information regarding the anonymous CVS: http://www.ilogic.com.au/csound/.
Information page regarding the Linux Audio Development mail-list: http://www.bright.net/~dlphilp/lad.html.
All listings referred to in this article are available by anonymous download in the file ftp://ftp.ssc.com/pub/lj/listings/issue58/3187.tgz.