Convert APNG (Animated PNG) to UIL

Animated Portable Network Graphics (APNG) is an extension of the Portable Network Graphics (PNG) format designed to support animated images. Introduced in 2004, APNG allows for animated sequences while retaining backward compatibility with non-animated PNG files. This format is utilized for its lossless compression, making it ideal for web graphics where image quality is paramount. APNG files are widely used for animated icons, logos, and other elements that benefit from high-quality animations without the artifacts common in GIF files. Its concise, efficient structure makes it a preferred choice among developers and designers focused on optimizing web performance.

The UIL file extension stands for User Interface Language and is associated with the X-Motif UIL Table. It is a plain text file format used by the UIL compiler to create user interfaces for the X Window System. UIL files define menus, buttons, dialog boxes, and other graphical user interface components. Introduced by The Open Group, this format allows developers to describe the initial state of a user interface, including widgets, resources, and callbacks. The UIL file is compiled into a UID file, which can be accessed by Motif Resource Management functions within an application.