Ranked in these QuestionsQuestion Ranking
Pro Free and open source
HexChat is available as a free download with source code licensed under GPL v2 and available on GitHub.
Pro Simple, clear interface
HexChat's default interface is clear, well-organized and intuitive. Channels can be laid out as both tabs and in a tree structure. All components such as user lists, topics bar or even menu bar can be hidden to provide a clean way to interact. Conversely the interface can be configured to show quick access buttons for changing channel flags, sending files or performing operator actions.
Pro Works for any level of user
HexChat is an advanced IRC client that is good for beginners as well as those users who like to get under the hood. It is easy to get up and running, but has all the advanced features that a power user would need.
Pro Functionality can be extended with plugins and scripts
HexChat has a great list of plugins and scripts and is compatible with most XChat plugins. XChats library is incredibly extensive. There is a wide range of both useful and fun plugins. It's possible to add an RSS feed, play a game of chess or control an mp3 player via chat while translating everything written to l33t speek.
Windows , Linux and Mac. Source-code available. Someone named Berke Victor's responsible for the Mac version. It's not maintained by the github team (Win, Linux, source-code).
Pro Highly customizable look
While most clients allow changing the theme or style of a window, HexChat gives complete control over what it looks like. It's possible to set a custom image as the background, changing font, or syntax colors.
Pro The Win10 Store Trial Is actually the full version
The Win10 Store "trial" is actually the full version and is not time limited - the pay version is simply there to give Windows Store users the ability to donate to the project, because the Windows Store doesn't support a donate button.
Pro Available in multiple languages
HexChat has either complete or partial translations in over 50 languages.
Pro Highly scriptable
HexChat supports scripting in Perl and Python. Both languages can be used to extend functionality of the software - bots can be written, automation can be added, new dialogs can be created.
Pro Actively developed
GitHub repository shows active development.
Pro Automation tools built into core application
Lots of automation features built into the core application. Custom keyboard shortcuts and Alias commands enabled. Winamp, url-logger, and many other plugins can be easily enabled for extra functionality. UI is highly configurable/themeable, large community of users. Supports countless simultaneous connections.
Con It is not free on Windows Store
Caused by Windows Store way of installing. If you select install trial, you have full use without limit. Don't use Windows Store.
Con Bad character support
Writing normal apostrophes and certain characters is not possible without a certain plugin installed.
Additionally, it does not render all glyphs like most other programs would.
Con Poor high DPI display support
Text is blurry and hard to read on HDPI displays. Both in Windows and Mac.
Con High CPU usage on some Windows 8.1 & 10 versions
HexChat has a long-standing unresolved issue with high CPU usage spikes on key-presses that is noticed in some Windows 8.1 and 10 versions.
Con Doesn't support fingerprint verification for SSL certificate
Doesn't support certificate fingerprint verification for SSL certificates. Hence can't use self-signed certificates for SSL.