comparison of instant messaging protocols 

Statements about this table:
gadu - gadu do not have the same creator as toc2
5 of the protocol have an open standard license
the yahoo! protocol do not have the same transport layer security as irc
skype have a different level of batch file sharing from zephyr notification service
protocol
creator
license
transport layer security
bulletins to all contacts
batch file sharing
gadu - gadu
gg network
proprietary
yes
no
yes
irc
jarkko oikarinen
open standard
yes , depending on individual server support
no
no
windows messenger service
microsoft
proprietary (discontinued)
no
yes
no
msnp ( windows live messenger , etc)
microsoft
proprietary
no
no
yes
( mumble )
thorvald natvig
open standard
yes
no
yes
protocol
creator
license
transport layer security
bulletins to all contacts
batch file sharing
oscar ( aim , icq )
aol
proprietary
yes (aim pro , aim lite)
no
yes
rvp ( windows messenger , etc)
microsoft
proprietary (discontinued)
no
no
no
sip / simple
ietf
open standard
yes
yes
yes
steam friends
valve corporation
proprietary
proprietary
yes
no
skype
skype
proprietary
proprietary
no
yes
protocol
creator
license
transport layer security
bulletins to all contacts
batch file sharing
toc2
aol
proprietary (discontinued)
no
no
partial
xmpp / jingle ( google talk )
jeremie miller , standardized via ietf
open standard
yes
yes
yes
ymsg ( yahoo! messenger )
yahoo!
proprietary
no
yes
yes
zephyr notification service
mit
open standard
no
yes
no