Here is a list of known Gnutella clients (dead and alive):

Code Name
----------------
BEAR BearShare
CULT Cultiv8r
GNOT Gnotella
GNUC Gnucleus
GNUT Gnut
GTKG Gtk-Gnutella
HSLG Hagelslag
LIME LimeWire
MACT Mactella
NAPS NapShare
OCFG OpenCola
OPRA Opera
PHEX Phex
QTEL Qtella
SNUT SwapNut
SWAP Swapper
TOAD ToadNode
XOLO XoloX
ZIGA Ziga

Registered vendor codes http://wilm.nl/gnutella/wiki/ServentVendorCodes
GDF Database (registered users only, stupid) http://groups.yahoo.com/group/the_gd...tAt=&prntRpt=1

Hope it helps & Greets, Moak

PS: As far as I know the vendor codes should be treated case insensitive. As you see all vendor codes are a 4 character code, new clients can use 4 spaces as temporary name.