.MULIB File Extension
What is a MULIB file?
Library created and used by Muse, an application used to design web sites without writing code; contains page elements such as site images, guides, color swatches, customized widgets, logos, embedded HTML, and graphic styles.
The MULIB file makes it easy to share libraries with other users. In Muse, you can export a library item and upload it to the Adobe community where other people can download the MULIB file and import it into their libraries.
The library panel allows you to quickly access items and add them to pages on your site. It also enables you to access commonly used elements for multiple pages.