Widgetset

Widgetsets support platform-sensitive development with the Lazarus IDE system. They act as adapter libraries that provide an interface between a platform-independent sourcecode written in Free Pascal and platform-specific system functions. Thus they allow for development of platform-native software without requiring to provide specific source code for different target platforms.

Interaction of class libraries and widgetsets in Lazarus and Free Pascal

Widgetsets act as basis for the Lazarus Component Library (LCL).

Available widgetsets

Currently (June 2020), the development status of widget toolkit interfaces is roughly as follows:^[1]

Widget set	Supported operating systems	Status
Windows API, GDI	Windows	Mainstream use
Windows CE API, GDI	Windows CE	Mainstream use
GTK+ 1.2.x	Linux (via X11)	Deprecated
GTK+ 2.8+	Linux (X11 and framebuffer), Windows, and Mac OS X (via X11)	Mainstream use
GTK+ 3.x	As Gtk2	Alpha
Qt 4.5+, 5.6+[2]	Linux (X11 and framebuffer), Windows, Mac OS X	Mainstream use. Works in Windows, Linux, Mac OS X, Maemo, etc
Cocoa	Mac OS X	In progress
Carbon	Mac OS X	Mainstream use
fpGUI	Windows, Windows CE, Linux (via X11)	Initial stage
Lazarus Custom Drawn Controls	Android, Windows, Linux (via X11), Mac OS X	Initial stage