LuaIRC is a fully featured IRC framework written entirely in Lua. It provides an event driven system for connecting to IRC servers and responding to actions such as messages, joins/parts, and channel mode changes, among other things. DCC SEND is also fully implemented, both for sending and receiving files.
This module requires LuaSocket (http://www.cs.princeton.edu/~diego/professional/luasocket/) and Lua 5.3. To install, modify the Make.config file with paths appropriate to your system and run 'make install'.
LuaIRC has only been tested on Freenode and Libera.chat so far, but I plan to expand this to other servers in the future. It's quite possible that it works on other servers anyway, however, so feel free to try it out, and send in bug reports for things that break.