LGI is an open source GUI framework (on Phabricator) for abstracting out all the operating system dependencies that you can produce portable code. It handles all the graphical interface functions, threading and semaphores, network connectivity and lots of other bits and peices to help build small, fast and reliable applications.

The strengths of LGI is that it's a small enough library that one person can understand it all. Also it's not too much of a burden on an application, both in increased download time and memory footprint. Ultimately however size is a secondary consideration to the core feature of LGI and that is portability. Currently 3 serious ports exist: Windows, Mac and Linux. There is also Haiku/BeOS and SDL ports which are partially implemented.

You can build some basic documentation using doxygen and there is some scripting language docs. Mostly though a good place to start is looking at the apps with source code:


Latest Trunk Code:

hg clone https://phab.mallen.id.au/source/lgi/ lgi/trunk


Developer environement GUI:
2.7 MiB, 12/11/2018

Resource Editor:

Graphical editor / translation for resource files:
0.9 MiB, 12/11/2018


Cross platform and version control user interface (Git/Hg/Svn/Cvs):
OSX x32
glibc 2.27
2.4 MiB, 23/11/2018
1.3 MiB, 23/11/2018
5.1 MiB, 20/5/2018

Ports Status

Ordered by maturity:
  • Win64 (Win10/11)
    This is the most stable and featured port, as it's the plaform I use the most. Everything works in Windows, and it's the fastest due to the speed of the Win32 Graphical Subsystem. I no longer support or test on any version of windows before Win10. The GTK port also works on Windows and you can compile with MingW as well. Windows x86/32bit is no longer supported.
  • Mac OS X (>=10.15)
    The current port of Lgi uses the Cocoa API (as of late 2019), and is mostly stable. I run MacOSX 12 so that's where the testing is happening.
  • Linux/GTK3 (Ubuntu >= 16.xx)
    Stable port for GTK3. Runs great in Ubuntu, less so in Debian. Runs on both x86 and ARM instruction sets. Yes, it's fine on a Pi.
  • Haiku Beta4 (BeOS)
    The BeOS / Haiku port is being removed from Lgi. back! The Haiku branch was merged back into the default trunk code early 2023. Main issues at the moment are nested dialogs not working well, popups and keyboard focus not working great. And some notifications not cross thread/BWindow boundaries well.
  • SDL
    The SDL port has some GUI functionality. It's not used much. Font support via Freetype2. There isn't any support for overlapped windows but you can still create simple apps that use the whole frame per window.

Config File

There is some documentation for configuring Lgi at runtime via the lgi.json file.


Building LGI

First check out the source:
hg clone https://phab.mallen.id.au/source/lgi/ lgi/trunk


Support Libraries

For full graphics and charset support download (or check you already have) iconv, libpng and zlib, libjpeg; then add their include paths to your compilers include paths. Or find the defines in Lgi.h for the various libraries and set them to 0.

Visual Studio

Install a supported version of Visual Studio: 2019 or 2022.

Adding build folders to the shared library path:

Add this to your path:
  • ./lgi/trunk/lib


Install XCode

Go to the Apple Developer site and grab XCode


Open Lgi.xcodeproj in XCode and run the build command.


Building on Ubuntu:
sudo apt-get install mercurial libmagic-dev libgtk3.0-dev \
    libgstreamer1.0-dev libappindicator3-dev libssh-dev
hg clone https://phab.mallen.id.au/source/lgi/ lgi/trunk
cd lgi/trunk
ln -s Makefile.linux makefile
make -j 4
If apt can't find the gtk 3 dev libraries, on some systems it's called 'libgtk-3-dev' just to be different I guess.

If the makefile doesn't work on your system:
  • Download a binary of LgiIde
  • Project->Open and select lgi/trunk/Ide/LgiIde.xml
  • Project->Create Makefile->Linux
  • Project->Build