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:

• Scribe
• i.Hex
• FileTeePee

Latest code:

git clone https://github.com/memecode/lgi.git lgi/trunk

IDE:

Developer environement GUI:

	Windows Win10+
v1.0 Stable	Zip 2.7 MiB, 12/11/2018

Resource Editor:

Graphical editor / translation for resource files:

	Windows Win10+
v4.1 Stable	Installer 0.9 MiB, 12/11/2018

Lvc:

Cross platform and version control user interface (Git/Hg/Svn/Cvs):

	Windows Win10+	OSX x32 10.10+	Linux x64
v0.4 Alpha	Zip 2.4 MiB, 23/11/2018	Zip 1.3 MiB, 23/11/2018
v0.1 Alpha			Zip 5.1 MiB, 20/5/2018

• 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 (>=12)
  The current port of Lgi uses the Cocoa API (as of late 2019), and is mostly stable. I run MacOSX 12-15 so that's where the testing is happening.
• Linux/GTK3 (Ubuntu >= 22.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 Beta5 (BeOS)
  There is some experimental Haiku support. Currently not running very well (circa Nov 2025).
• 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.

• Data storage classes
  • LArray<T> - templated array
  • LString - pythonic string class (think std::string but more flexible)
  • LUnrolledList<T> - hybrid list of short arrays
  • LStream - generic stream interface
    • LMemQueue - FIFO queue in fixed size blocks
      • LStringPipe - add string handling
    • LMemFile - little used in memory file (probably should be deprecated)
    • LMemStream - wrap memory in a stream interface
    • LStreamTee - send data to multiple other streams
    • LStreamConcat - read multiple streams as one logical file
    • LZlibFile - read / write compressed data
• File system abstraction:
  • LFileSystem
    • LVolume - access disk info
    • LDirectory - read folder contents
    • LFile - general file i/o
      • LFile::Path - path handling
• User interface elements:
  • LWindow - core top level window
  • LDialog - modal or modeless dialogs
  • LView - main view parent class
  • Layout:
    • LBox - Split into "n" panes, vertically or horizonally
    • LTableLayout - Html table like layout control
  • Containers:
    • LLayout - add scroll bar support to something
      • LItemContainer - generic container of LItem and LItemColumn.
        • LList - list of items
        • LTree - tree of items
          • LControlTree - A tree of settings with suitable edit controls
        • LSortable - parameters for sorting
    • LTabView - array of tabs, each with their own content
    • LMdiParent, LMdiChild - tabbed multi-document view
    • LToolBar - container for LToolButton
    • LStatusBar - container for LStatusPane
  • Text editing:
    • LEdit - Edit control (Win32: Native, Mac/Linux: LTextView3)
    • LTextView3 - Unicode text editor
    • LRichTextEdit - Rich text editor (can read/write basic HTML)
      • Testing and development: HtmlEditor
  • LCheckBox - Boolean control (On/Off)
  • LTextLabel - Label
  • LRadioGroup, LRadioButton - Select one of many options
  • LCombo - Combo box
  • LBitmap - Image display
  • LProgress - Progress meter
  • LSlider - Slider control
  • LScrollBar - a scroll bar, often using the context of LLayout
  • LHtml - HTML renderer, with some CSS and scripting support
    • Testing and development: HtmlViewer
  • LMenu, LSubMenu, LMenuItem - Menu controls
  • LPopup - Popup windows
  • LToolTip - Tool tips
• Internally all text is Utf-8.
  • Unicode.h
• Unicode font support:
  • LTypeFace - font info base class
    • LFont
      • LEmojiFont - emoji rendering
  • LFontSystem
  • LFontCache - cache for creating and reusing CSS fonts
  • LDisplayString - rendering text
  • LFontSelect - user interface for choosing a font
  • Tools for converting to/from native OS text and other codepages are provided. iso-8859-x and windows-12xx codepage support is native, other codepages supported via the iconv library.
• Multi-threading:
  • LThread - run code in worker threads
  • LMutex - lock resources for multi-threaded access
  • LThreadEvent - signal event in different threads
  • LEventTargetThread - handle events in a thread
• Sub process management:
  • LSubProcess - run separate processes
• Graphics library:
  • LSurface
    • LMemDC - in memory bitmap
    • LScreenDC - drawing to screen
    • LPrintDC - print support
    • Supports internally, all the basic primitives: Line, Circle, Rect, Blt, Flood, Polygon, Ellipse etc. No OS support required.
    • Bit depth conversion for bitmaps and colours.
    • Palette management.
    • Alpha blending.
  • LDisplayInfo
  • Vector art:
    • LPath
    • anti-aliased rasterisation of primitives & text.
    • Includes TTF -> path capability.
  • LFilter - image file format support:
    • jpeg (via libjpeg)
    • png (via libpng and zlib)
    • svg (via lunasvg)
    • gif
    • tiff
    • bmp
    • ico
• Full OS independant file open/save dialog (LFileSelect) There is also support for the Win32 and Mac native file open/save dialogs (API compatible).
• Mime type detection lookup API with support for finding a suitable app for a Mimetype.
  • LGetFileMimeType
  • LGetAppForMimeType
  • LMime - rfc822 message parsing
• Platform independant XML resource file format for strings, dialogs and menus. All fully multi-lingual.
  • LgiRes is a graphical editor for this format.
  • LResourceLoad, LLoadString
• Clipboard IO for text, bitmaps and binary data:
  • LClipBoard
• Drag'n'drop events/API:
  • LDragData
  • LDragFormats
  • LDragDropSource
  • LDragDropTarget
  • LDropFiles
• Commonly dialogs:
  • LInput - get textual input from user.
  • LgiMsg - standard message dialog.
  • LAlert - customizable button dialog.
  • LFindReplace
• Date time handling:
  • LDateTime
    • Date subtraction/addition
    • Conversion to/from native format
    • Conversion to/from strings
  • LTimeStamp
  • LDstInfo
  • LTimeZone
• Network support:
  • LSocket - socket base class
    • OpenSSLSocket - SSL socket
    • LUdpListener - listen for UDP messages
    • LUdpBroadcast - broadcast UDP
    • LSocks5Socket - SOCKS5 proxy
  • LSelect - select wrapper, wait on events
  • LSsh - libssh wrapper
  • Protocol support:
    • IFtp
    • IHttp
    • MailSmtp
    • MailPop3
    • MailIMap
    • IDns
    • LHostnameAsync
    • LTelnet
• Structured data formats:
  • LXmlTree - XML i/o
    • LXmlTreeUi - xml <-> UI helper
  • LJson
• Scripting:
  • LDom - API to connect the scripting to external classes
  • LVariant - common variable class
  • LScriptEngine - high level compile + run class
    • LCompiler - converts script to LCompiledCode
    • LCompiledCode - compiled script
    • LVirtualMachine - runs LCompiledCode objects
    • SystemFunctions - available API

Building LGI

git clone https://github.com/memecode/lgi.git lgi/trunk

cd lgi/trunk/deps
./build.py

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