A Hotline client with a GTK+ interface.

Screenshots from the project's README.

GtkHx is a client for Hotline, the chat and file-sharing system from 1996. A Hotline server is a small community of its own: a public chat room, private messages, a shared file library, and a news board, all run by whoever hosts it. Trackers list the servers that are up, so you can go looking for one.

GtkHx was first written in 2000 for GTK+ 1.2. It has since been rebuilt for GTK 4 and libadwaita, and much of it rewritten in Rust, while staying fully compatible with the Hotline 1.2, 1.5 and 1.9 servers still running today.

From the project's README.

Website | Source code

• Video
• Video chat and screen sharing, on servers that support it
• A dockable Video panel shows everyone's camera and screen, plus your own preview
• Choose a camera in Settings → Voice
• Camera tiles keep the same order, by user, instead of shuffling between calls
• Voice
• Fixed occasional audio problems after joining or rejoining voice
• Themes and Icons
• Themes now color the whole window, not just the chat
• Richer chat colors, and each nickname keeps its own color
• New icons that match the desktop and follow the theme's colors
• The original pixel-art icons live on in the new Classic theme
• New Neon Doll theme
• Settings → General can keep the system's window colors around a themed chat
• Files
• The file browser is now its own window, one per connection
• Clearer layout, with labeled Download and Upload buttons
• Right-click a file for Open, Preview, Get Info, Rename, Delete and more
• User Interface
• Slimmer window chrome, so chat gets much more of the window
• The server banner and connection status now sit in the header bar
• The status bar is gone, and the toolbar is optional (off by default)
• Pane titles and action bars can be hidden
• Chat tabs stay hidden until there is a second conversation
• Settings opens with Ctrl+,
• Hotline Protocol
• Fixed file transfers with Windows clients and servers
• macOS
• GtkHx now asks for camera and microphone access
• Fixed a crash on macOS versions too old to run GtkHx
• Code Modernization
• GtkHx now shares its Hotline protocol code with the hxd-ng server
• Translations
• Translated the new strings

Downloads

• GtkHx-v1.4.0-macos-arm64.zip  (32.9 MB)
• GtkHx-v1.4.0-macos-x86_64.zip  (35.0 MB)
• GtkHx-v1.4.0-win64.zip  (70.4 MB)
• GtkHx-v1.4.0.flatpak  (11.0 MB)

• GtkHx v1.4.0 September 26, 2026

• Fixed issue with Linux Flatpak and bundled library paths
• News Browser
• Fixed double load issue
• Fixed a bug that prevented users from creating a new folder

Downloads

• GtkHx-v1.3.2-macos-arm64.zip  (31.9 MB)
• GtkHx-v1.3.2-macos-x86_64.zip  (33.9 MB)
• GtkHx-v1.3.2-win64.zip  (69.4 MB)
• GtkHx-v1.3.2.flatpak  (10.9 MB)

• Build
• Bundle fonts and translations for macOS and Windows packages
• Connections
• Include some more servers for new users
• User Interface
• Fix chat scroll bug

Downloads

• gtkhx-flatpak.zip  (10.9 MB)
• gtkhx-macos-macos-14.zip  (31.4 MB)
• gtkhx-macos-macos-15-intel.zip  (33.6 MB)
• gtkhx-windows.zip  (68.8 MB)

• Connections (formerly Bookmarks)
• Bookmarks are now Settings → Connections; the separate Bookmarks window is gone

• Each connection can override your nickname and icon for that server, or inherit the defaults from Settings → Identity

• Bookmarks are now kept in a single TOML file

• Legacy bookmark files are imported if the TOML file does not exist
• Connections can be exported to legacy Hotline bookmark files
• Built-in bookmarks can now be deleted
• Build
• GtkHx is now available for macOS and Windows
• Code Modernization
• GtkHx is now mostly Rust code
• Config
• The settings file (gtkhxrc) is now gtkhx.toml
• GtkHx will migrate the old gtkhxrc if one is present and no gtkhx.toml exists
• Fixed bugs in preferences along the way
• Hotline Protocol
• Fixed old bug with resumable file transfers
• Ensure that multi-byte names > 32 bytes get truncated at a character boundary
• Multiple Connections
• Users may now be connected to more than one server at a time, and switch between connections with tabs
• Sound
• Replaced libcanberra with rodio for notification sound playback
• Translations
• Updated existing translations
• Added Japanese translations
• User Interface
• Button icons now default to their original size, rather than upscaled
• Brand new hxchat widget for Chat (replaces forked version of HexChat's xtext)
  • Significantly better performance
  • Markdown support (toggleable)
  • Icon display next to speaker (toggleable)
  • Speaker grouping, so doesn't have to keep appearing on every consecutive line
  • Right clicking on a speaker's name or icon will now pop up a "user" popup menu
  • Chat history can be searched via Ctrl-F
• Ctrl-U now works to clear any input in the app
• [Enter] in the Connect dialog now connects
• Handle character conversion on user list and user info
• Closed panels/windows will not reopen on startup
• Docking a window will now highlight the pane that is being targeted
• Panel foreground state is now persisted

Downloads

• GtkHx-v1.3.0-macos-arm64.zip  (31.5 MB)
• GtkHx-v1.3.0-macos-x86_64.zip  (33.7 MB)
• GtkHx-v1.3.0-win64.zip  (69.3 MB)
• GtkHx-v1.3.0.flatpak  (10.9 MB)

• Voice
• Voice activity detection for self
• Volume control slider for each individual
• Sounds for join / leave events
• Update to follow latest version of the voice chat spec
• Code Modernization
• Parts of GtkHx's UI are now written in Rust

Downloads

• gtkhx.flatpak  (10.2 MB)

Small follow-up release following the big 1.2.0 release to address some bugs

• User Interface
• Move Join Voice/Mute buttons to the User list
• Bug Fixes
• Make sure Files browser resets to root directory between sessions
• Fix emoji picker related crash when closing private chat/message tabs
• Fix issue with GtkHx reporting task errors for ICON_GETLIST when unavailable
• Don't auto fetch 1.5+ News if server version is <150
• Fix Hotline protocol regression with large frames introduced in Rust hxnet migration

Downloads

• gtkhx.flatpak  (9.8 MB)

• User Interface
• GtkHx theme support
• Emoji shortcode support with typeahead completion
• Agreement text is now rendered in a monospace font
• Cleaner Settings dialog
• Code Modernization
• GtkHx's networking code is now in Rust
• Address GTK+ 4 deprecations
• Hotline Protocol
• GIF icon support
• Bug Fixes
• Various voice chat fixes
• Compatibility Fixes
• Support for glycin 1+ and 2+ loaders
• rustc dependency dropped to 1.8.5
• Voice chat and its dependencies are now optional

Downloads

• gtkhx.flatpak  (9.8 MB)

• Voice chat
• Inline media
• User Interface
• New multi-panel interface with support for custom layouts and undocking panels into their own windows so that users can still have the nostalgic multi-window experience if they prefer
• Dropped custom GtkHList in favor of GtkColumnView
• Results from different trackers are nested in their own result sets
• Added support for hotline:// links
• Made the News 1.5 browser handle links in the posts
• Code Modernization
• Parts of GtkHx are being rewritten in Rust
• Bug Fixes
• Handle Chat subjects with Mac Roman characters
• Fixed icons in Private Chat user list
• Fixed an issue where creating new user accounts was not working
• Hotline Protocol
• Tracker v3 support
• Support for fetching tracker listings via TLS
• Dropped RC4 cipher support. RC4 is weak/insecure and should not be used.
• Handle servers that echo request opcode in TASK replies
• Settings
• Dropped *(X|Y)POS config keys as GTK+ 4 does not support getting the window position

Downloads

• gtkhx.flatpak  (8.2 MB)

• General
• Tons of fixes, especially for modern systems / 64-bit architectures
• XDG-compliant config (~/.hx/ -> ~/.config/gtkhx/ and ~/.gtkhxrc -> ~/.config/gtkhx/gtkhxrc)
• Created GtkHx icon and .desktop file
• Admins can now send server broadcasts
• Updated icons.rsrc to include icons from HLC 1.9
• New machine-generated translations for French, German, Spanish, and Portuguese
• Debug logging support with HL protocol tracing
• SOCKS support is now available via the system's NetworkManager
• Flatpak package support
• Scrapped Plugin support for now
• Better file preview support (support common image types, PDF, source code, markdown)
  • Optional libpoppler dep for PDF file previews
  • Optional libgtksourceview dep for markdown / source code file previews
  • Optional ImageMagick dep for QuickDraw PICT previews
• Code Quality
• Unit tests
• Integration tests that run against mhxd and Janus instances
• Fixed all compilation warnings
• Code Modernization
• GTK+ 1.2 -> GTK+ 4.x + libadwaita
• Rewrote threading/event model
• Use libgsound / libcanberra instead of executing binary to play sounds
• Networking code rewritten to use GSocketClient/GIOStream
• GtkHx now uses an event driven architecture
• Leveraged GLib data types
• Switch to meson for build system
• User Interface
• Totally revamped Settings window
• Brand new News browser
• Brand new orthogonal file manager type Files browser
• Wide format icon support
• Pre-1.5 News now has a text search feature
• Tracker search case sensitivity can now be toggled in the Tracker window
• New Bookmark manager dialog allows for in-app management of Hotline bookmarks
• URLs in Chat / Message / Private Chat / News can now be right clicked
• Emoji picker next to Chat and Message input fields
• System notification support
• Systray support via libayatana-appindicator
• Prevent/block user actions that the server does not allow
• Server banner support (both URL, which pulls in libsoup, and native HTXF)
• Cleaner Task row design
• Light/Dark theme support
• Hotline Protocol
• Better protocol support for all protocol versions
• Do not attempt to fetch News/Agreement if the user does not have permission
• PING support
• Fixed issue with file protocol list handling that prevented showing all contents of a directory
• Addressed issue with GtkHx not identifying client type with HOPE negotiation
• Support for ZSTD and LZ4 HOPE compression algorithms
• Support for CHACHA20-POLY1305 HOPE stream cipher
• Support for native UTF-8 extension
• Support for large file transfers (>4GB) extension
• Support for chat history extension
• Support for colored names extension
• Support for TLS encrypted connections

Downloads

• gtkhx.flatpak.gz  (6.7 MB)