MegaMAX - A collection of user interface objects and other externals for use with Opcode's MAX programming environment. - http://www.musikinetix.com/MegaMax/MegaMax.html
PeRColate - Collection of synthesis and signal processing objects for Max/MSP. By Dan Trueman and R. Luke DuBois. - http://www.music.columbia.edu/PeRColate/
VBAP - Vector Base Amplitude Panning, objects for multi-channel 3-D sound - http://www.acoustics.hut.fi/~ville/
Bomb - A visual-musical instrument. - http://draves.org/bomb/
Lobjects by Peter Elsea - FTP-site for download of Lobjects, Peter Elseas collection of externals for dealing with lists. - ftp://arts.ucsc.edu/pub/ems
Real Time Composition - Patches for MAX offering compositional techniques like serial procedures, permutations and controlled randomness. - http://www.essl.at/works/rtc.html
CNMAT MAX Work - Patches and Objects from UC Berkeley's CNMAT - http://www.cnmat.berkeley.edu/Max