UDP/Datagram socket support

Analysis of support in underlying implementations

Implementation method Support for time-out/efficient waiting
SBCL Yes (BSD sockets) Yes, select()
CLISP Yes, through raw sockets SOCKET:SOCKET-STATUS works for raw sockets
CMUCL Yes (unix module; BSD socket API) Yes, select()
Scieneer Probably (stems from CMU) Yes, probably select()
Allegro Yes Yes, mp:wait-for-input-available [input only :-( ]
OpenMCL Yes (Same API as Allegro) No (or select and FFI)
LispWorks? merged from LispWorks?-UDP (non-official) select / WSAEventSelect
ECL Yes (BSD sockets) Yes, BSD sockets through clines
ABCL Yes, same way as stream and server sockets: with 'FFI' Yes, through Selectors, Channels etc
MCL No Kqueue