irc-otr is a collection of plugins for IRC clients (currently irssi, xchat, and weechat) for Off-The-Record Messaging (OTR). OTR lets you have encrypted private conversations and also supports deniability. There is no support for channels though. This plugin is probably most useful in conjunction with BitlBee, the IM-to-IRC gateway, since OTR is mostly used in IM protocols (clients like pidgin/kopete/adium/... support it).
Fetching & Building
Check them out from irc-otr's git repository.
git clone git://git.tuxfamily.org/gitroot/irssiotr/irssiotr.git cd irssiotr mkdir build cd build cmake -DWEECHAT_INCLUDE_DIR=<your_weechat_sources>/src/plugins .. make cp irc-otr.so <your_weechat_plugins_dir>
You should definitely check out the README. A few features are still missing in weechat but the important stuff is there.