When comparing Foo IRC vs KVIrc, the Slant community recommends KVIrc for most people. In the question“What are the best IRC clients for Windows?” KVIrc is ranked 6th while Foo IRC is ranked 11th. The most important reason people chose KVIrc is:
Help files and online resources show all of the feature and scripting capabilities.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Lots of customization options
Pro Consistent looks and function as a UWP app
Being a Universal Windows Platform app, FooIRC follows the design guidelines set forth by Microsoft, which allows it to look native to the UI. This also means things such as notifications integrate well with the notification center.
Pro Great, simple UI
Pro Plugin support
Pro Supports DCC
Pro Extensive documentation available
Help files and online resources show all of the feature and scripting capabilities.
Pro Portable
KVIrc does not need to be installed. It can be kept on a flash drive and run from there.
Pro Still active developement
Despite whats been said, development has been continuing at a steady pace on version 4.3.1 and more recently 4.3.2.