Hexchat
HexChat is an IRC client based on XChat, but unlike XChat it's completely free for both Windows and Unix-like systems.
Spyware Level: Not Spyware
Hexchat is not spyware in and of itself, however you can use it to connect to services that may be spyware. Hexchat is also distributed on spyware platforms such as the Windows Store. If you want to download Hexchat, download it from the developers' website instead of the Windows Store.