What does a file system have anything to do with IRC anyhow?
Because mIRC has features and scripting language features that access the file system, and the OP was talking about creating mIRC for the iPad.
The reasons why apps can't access the file system aren't important; just that they can't.
I'm sure there are lots of other things mIRC would be unable to do on an iPad, that was just one that sprang to mind.
