Over at Konversation, we implemented our bidi text behavior with the help of KDE's Arabic and Hebrew translators. Not only do we render the words correctly RTL,

Over at Konversation, we implemented our bidi text behavior with the help of KDE's Arabic and Hebrew translators. Not only do we render the words correctly RTL, we also switch the overall directionality of the line based on the implied direction of the majority of characters within it, i.e. a line containing predominantly Arabic will be aligned to the right of the window with the nickname to the right of the message. This makes it rather pleasant to use for Arabic channels. Edit: And I should mention that to my knowledge, KDE's terminal emulator Konsole will render Arabic text correctly as well. However irssi would need to do the alignment part.