Little Forms is an open source (but note) minimalistic GUI widget library written in plain C89. It currently supports Windows and X11 backends (for Linux, FreeBSD, Mac OS X and other systems that provide the X11 API).

The goal of Little Forms is to provide a simple and cross platform C GUI toolkit with a stable API once version 1.0 is released (see API Stability). The current style is designed after Window Maker, which itself was designed after NeXTSTEP and GNUstep.