Miranda NG is a multi-protocol instant messaging client supporting most common protocols by default including Facebook, GG, ICQ, IRC, Jabber and MRA. However, additional protocols are also available including Discord, Skype, Tox, Twitter etc., as well as plugins and languages via “Main menu > Available Components list” (see online list).
As the program is a code fork of Miranda IM, an FAQ about the differences is available.
Alternatively, Miranda NG Portable is also available.