GtkHx is a GTK+ Hotline Client originally based on Hx. Originally written in C, and currently being rewritten in Rust.

Features

• Modern GTK+ 4 / libadwaita / libpanel UI with retro look and feel
• Full TLS support, for servers, file transfers, and trackers
• Cross platform – works on Linux, macOS, and Windows
• Support for extended Hotline protocol features and capabilities
  • Voice chat
  • Inline media
  • Native UTF-8
  • GIF icons
  • Large file transfers
  • Chat history
  • Colored names
  • Blowfish and ChaCha20-Poly1305 cipher support
  • Tracker v3
• File previews
  • Common image types via glycin
  • QuickDraw PICTs via ImageMagick
  • PDFs via libpoppler
  • markdown / source files via libgtksourceview
• Orthogonal file manager
• Customizable UI allows for single window and multi window layouts
• Themable, with support for light and dark themes
• Systray and app notifications

History

GtkHx was originally created in 2000, with work on it ceasing in 2003. In 2026, the original author, Misha Nasledov, resurrected GtkHx as a modern application with the latest Hotline protocol extensions.