Nuklear is a minimal, header-only graphical user interface toolkit written in C. It utilizes an immediate-mode rendering model, where the interface is reconstructed and drawn directly within the application loop each frame. This approach eliminates the need for persistent widget state or complex synchronization between the interface and underlying application data.
The library is designed for portability and integration into resource-constrained environments. It requires the host application to manage memory manually, allowing it to function in systems that lack standard library support. By decoupling the interface logic from the graphics API, the library remains platform-agnostic, requiring only custom vertex and index buffer drawing functions to render elements.
The toolkit includes a built-in engine for UTF-8 glyph rasterization, enabling the display of international character sets and global languages without external text layout dependencies. Developers can customize the visual appearance and styling of interface elements to align with specific design requirements. The entire codebase is distributed as a single file to simplify integration and remove the need for external build systems.