Open XML Paper Specification (also referred to as OpenXPS) is an open specification for a page description language and a fixed-document format. Microsoft developed it as the XML Paper Specification (XPS). It is an XML-based (more precisely XAML-based) specification, based on a new print path (print processing data representation and data flow) and a color-managed vector-based document format that supports device independence and resolution independence.
This format is used for storing several types of bitmaps, including animations. MNG allows you to store lossy and lossless images with compression. This format provides you with more options than GIF for saving animated files while keeping the original image size.