A tiny, portable, immediate-mode UI library written in ANSI C
- Tiny: around 
1100 slocof ANSI C - Works within a fixed-sized memory region: no additional memory is allocated
 - Built-in controls: window, scrollable panel, button, slider, textbox, label, checkbox, wordwrapped text
 - Works with any rendering system that can draw rectangles and text
 - Designed to allow the user to easily add custom controls
 - Simple layout system
 
if (mu_begin_window(ctx, "My Window", mu_rect(10, 10, 140, 86))) {
  mu_layout_row(ctx, 2, (int[]) { 60, -1 }, 0);
  mu_label(ctx, "First:");
  if (mu_button(ctx, "Button1")) {
    printf("Button1 pressed\n");
  }
  mu_label(ctx, "Second:");
  if (mu_button(ctx, "Button2")) {
    mu_open_popup(ctx, "My Popup");
  }
  if (mu_begin_popup(ctx, "My Popup")) {
    mu_label(ctx, "Hello world!");
    mu_end_popup(ctx);
  }
  mu_end_window(ctx);
}- See 
doc/usage.mdfor usage instructions - See the 
demodirectory for a usage example 
The library expects the user to provide input and handle the resultant drawing commands, it does not do any drawing itself.
The library is designed to be lightweight, providing a foundation to which you can easily add custom controls and UI elements; pull requests adding additional features will likely not be merged. Bug reports are welcome.
This library is free software; you can redistribute it and/or modify it under the terms of the MIT license. See LICENSE for details.