EPIC is 100% backwards compatible with ircII because EPIC is ircII. EPIC was originally built upon the ircII 2.6 client and has maintained faithfulness to remain current up to the 2.8.2 release.

EPIC is slightly larger than ircII-4.4 (about 40k on this system), but that is mostly because of the multitude of new features, the dual ANSI/K&R compliant function headers, and the large amount of re-written code in an attempt to make ircII faster, more efficient, and more powerful.

EPIC is derived directly from IRC-II which is currently maintained by Matthew Green, and includes in whole all the additions included in the “plus” clients by Jeremy Nelson and all of the modifications in the “mod” clients by Jake Khuon. EPIC is currently maintained by EPIC Software Labs (ESL), comprised of Jeremy Nelson, Jake Kuhon, Robert Chady, and a cast of a dozen others.

• EPIC is completely safe: There are no hidden trap doors. We value your trust, and will not do anything to abuse it.
• EPIC is programmable: While ircII does contain a wide range of commands and functions, several glaring omissions exist, which EPIC has attempted to fill, making the ircII language complete, precise, and efficient.
• EPIC supports bots: We do not agree with those who feel that script bots are all the evil of irc, and we feel that scripts bots must not be squelched by those who have the stranglehold of control on irc. EPIC will support bots for as long as we maintain it.
• EPIC is not anal retentive: EPIC allows you to do EVERYTHING that the irc protocol (RFC 1459) allows, and does not place any arbitrary restrictions upon you. EPIC does fully comply with the protocol as shipped and does not allow you to do anything that is deemed illegal by the protocol.
• EPIC is complete: EPIC supplies over 100 various functions and commands which allow you to do things very quickly things that required very large or slow scripts in the past.
• EPIC is fully ANSI-compliant: Most current versions of the stock client do have full prototyping for all functions, which has the same net effect as the work we have done. We, however, chose to provide both a “old” style (K&R) function header and a “new” style (ansi) function header with every function and provide every extern function a prototype in a header file.
• EPIC is getting smaller and faster: Changes are continually underway to provide a faster client with more functionality while using less CPU cycles. While these may appear to be conflicting goals, the whole point of the EPIC project is to provide the best client that runs as well as can be managed.