Instead of using scripts and bots to protect against channel floods it is now build into the ircd.
An example +f mode is: *** Blah sets mode: +f [10j]:15
This means 10 joins per 15 seconds are allowed in the channel, if the limit is hit, the channel will be set +i automatically.
The following floodtypes are available:
In fact, it can get even more advanced/complicated:
Instead of the default action, you can for some floodtypes specify another one, for example: +f [20j#R,50m#M]:15
This will set the channel +R if the joinlimit is reached (>20 joins in 15 seconds), and will set the channel +M if the msg limit is reached (>50 messages in 15 seconds).
There's also a "remove mode after X minutes" feature: +f [20j#R5]:15 will set the channel +R if the limit is reached and will set -R after 5 minutes.
A server can have a default unsettime (set::modef-default-unsettime), so if you type +f [20j]:15 it could get transformed into +f [20j#i10]:15, it's just a default, you can still set [20j#i2]:15 or something like that, and you can also disable the remove-chanmode completely by doing a +f [20j#i0]:15 (an explicit 0).
The old +f mode (msgflood per-user) is also still available as 't', +f 10:6 is now called +f [10t]:6 and +f *20:10 is now +f [20t#b]:10. Currently the ircd will automatically convert old +f mode types to new ones. Note that there's no unsettime feature available for 't' bans ([20t#b30]:15 does not work).
Channel mode j
The +f mode includes a feature to prevent join floods, however this feature is "global." For example, if it is set to 5:10 and 5 different users join in 10 seconds, the flood protection is triggered. Channel mode +j is different. This mode works on a per-user basis. Rather than protecting against join floods, it is designed to protect against join-part floods (revolving door floods). The mode takes a parameter of the form X:Y where X is the number of joins and Y is the number of seconds. If a user exceeds this limit, he/she will be prevented from joining the channel.