Sometimes people ask me what certain files do, or where to find something.

Files regarding epic's main event looper
========================================
irc.c		The startup and shutdown routines and the main looper
network.c	Hostnames and addresses and sockets, oh my!
newio.c		FD Multiplexing, data buffering, i/o callback generation.
ssl.c		Secure Socket Layer stuff
timer.c		Scheduling events to happen later
translat.c	Character set remapping

Files regarding talking to rfc1459 (irc) server
===============================================
server.c	Server lists and sending stuff to the server

Files regarding parsing of rfc1459 (irc) protocol
=================================================
parse.c		Everything the server sends us that isn't a numeric reply
numbers.c	Numeric replies
who.c		WHO, ISON, and USERHOST numeric reply handlers

Files that implement extensions and applications of rfc1459 (irc) protocol
==========================================================================
crypt.c		Simple bit-twiddling for irc messages
ctcp.c		Client To Client Protocol (Inquiry/Response protocol)
dcc.c		Direct Client Connections (p2p, uses CTCP as transport)
flood.c		Flood (too much crap too quickly) detection
ignore.c	A polite way to pay someone no mind
names.c		Channels, nicknames, modes, and userhosts
notify.c	Polling for the existance of other users on irc

Files that have some knowledge of rfc1459 (irc) concepts
========================================================
commands.c	Many irc commands have front end commands
functions.c	Many interfaces to irc stuff have functions to query info.
hook.c		Many event callbacks are irc related
vars.c		Many built in configurables are irc related

Files that regard the ircII programming language
================================================
alias.c		Unified symbol table, macro-commands and macro-variables
clock.c		Automatic system timers (notify, clock, and mail)
expr.c		Expression parsing and macro expanders
expr2.c		A better expression parser
if.c		Loop control commands
reg.c		Wildcard pattern matching
words.c		Finding and extracting words from a flat string

Files that implement features of the ircII programming language
===============================================================
array.c		Karll Arrays, faster data storage in unique namespace
commands.c	The commands of the ircII language
exec.c		The /EXEC command
files.c		The $open() function and friends.
functions.c	The functions of the ircII language
glob.c		The $glob() function
hook.c		The /ON command
perl.c		The $perl() function
queue.c		The /QUEUE command
tcl.c		The $tcl() function
vars.c		The /SET command (runtime configurables)

Files that regard the user interface
====================================
input.c		Logical interactive input processing
keys.c		Turning key presses into logical input-line actions
lastlog.c	Saving a copy of what has appeared on your window
log.c		Writing what apears on your screen to a file
logfiles.c	General purpose logging of all manner and sorts
output.c	Entry functions for all screen output.
screen.c	Back end display (wrapping/breaking/color/etc)
status.c	Summary information (at the bottom of) a window.
term.c		Low level display (termcap/terminfo)
window.c	Logical visual portals into a server.
wserv.c		Multiple physical screen support

Files that support other things without being directly related
==============================================================
alist.c		Resizable binary-searchable sorted arrays
alloca.c	Heap emulation of dynamic stack allocation
compat.c	Functions that we use that some systems do not have
debug.c		Output extra info to help diagnose problems
gailib.c	Emulate get(addr|name)info on IPv4-only systems
ircaux.c	Auxilliary functions for various purposes
ircsig.c	Signal handling
list.c		General purpose doubly-linked lists
mail.c		Mail checking