When comparing KVIrc vs Nettalk, the Slant community recommends KVIrc for most people. In the question“What are the best IRC clients for Windows?” KVIrc is ranked 6th while Nettalk is ranked 14th. 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 Extensive documentation available
Help files and online resources show all of the feature and scripting capabilities.
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.
Pro Portable
KVIrc does not need to be installed. It can be kept on a flash drive and run from there.
Pro Plenty of customization options
Pro Can overlay incoming messages
Nettalk can be set up to overlay incoming messages. Especially useful for games.
Pro Built-in spellcheck
Pro Free and open source
Pro Multi-lingual interface
Nettalk is available in English, Spanish, Dutch, Russian, Chinese, Hungarian and German.
Pro Easy interface
Simple and good looking interface.
Pro Encryption support
Pro Scriptable
Pro Functionality can be extended via plugins
Cons
Con No longer developed
Development ceased some time ago (2012).
Con Poor log management
It stores all logs in one file in a custom format.
Con German language
Is primarily a German language client, so the spell check, etc. is in German.