As polynomial-c announced last year, xchat upstream is dead for some time now. Fortunately for us the fork hexchat is taking over and is compatible with your current xchat configuration so it’s really easy to migrate.
migrating to hexchat
$ mv .xchat2/ .config/hexchat/ $ mv .config/hexchat/xchat.conf .config/hexchat/hexchat.conf
As mentioned in the comments by Louis Tim Larsen, if you have some servers configured with more than one channel make sure to run this command as well :
sed -i 's/,#/\nJ=#/g' ~/.config/hexchat/servlist.conf
Then run hexchat as you would xchat.
theme your IRC
$ cd .config/hexchat $ wget http://dl.hexchat.org/themes/Solarized%20Light.hct $ unzip -o Solarized\ Light.hct
Restart hexchat and enjoy your up to date and colorized IRC client.