IRC-client Showdown, Extreme Version
I love IRC. I try to keep all my common software on the shell in case I somehow loose my ability to use X. This also enables me to use global colorscheme and is performance-wise advantegous. There are many reasons to live in the shell (aside from web-browsing, which is a pain), but this is not the post to discuss them. Instead I want to make a quick comparison of IRC-clients.
I admit, I have not used all that many IRC-clients over the years, as they are usually indefinetely customizable and I tweak them for months before I decide to move on to a different one to start from scratch. Currently, I am using irssi, as I have not customized weechat to the extend I would like to yet.
I prefer irssi as it is simpler and more unix-style, using just one config, one theme and perl-extensions for every bit of bonus functionality. Weechat works out of the box like a charm. It includes a window-list which just has to be activated, automatic indentation of nicks, a nicklist which just has to be disabled, colored nicks, a trackbar and tons of more useful stuff. But the options are crap. It's superior to the irssi djungle of formats, inside formats, inside other formats, … but in my opinion there are not enough ways to change low-level stuff, weechat will always look like weechat, no matter what you do.
But I promised the extreme version in the title of this post, this is performance. On Twitch.tv, there is currently a stream called 'twitchplayspokemon', which is a pokemon hack that accepts button input via twitch chat (which is IRC). The corrosponding IRC-channel is used by 35k-38k people at a time, featuring tons of messages. It actually caused problems with the Twitch servers, which could not handel the concentrated load, but seems to run fine now.
Anyway, I tried using this channel with my IRC-clients. Weechat lags out on joining, becoming unresponsive while building the nicklist, which is hidden, but still active (this is what I mean by irssi is simpler). Then, after about a minute, it works. Weechat uses 56.5 MB of RAM on my system. That's insane. No fancy plugins, just one server, one channel, smart-filter enabled, no nicklist.
Irssi works like on any smaller IRC-network, without any noticable performance impact, using about 12 MB of RAM, which is more reasonable. For comparison though, connecting through netcat uses 644 KB of RAM. Of course, this is without logging, formatting or anything except just printing what the server sends me, but for IRC, netcat is actually sort of viable, in emergency cases.