XCF is a file extension for an image file native to GIMP. XCF stands for eXperimental Computing Facility. Similar to a Photoshop Document (PSD), XCF files support saving layers, channels, transparency, paths and guides, yet don’t support saving the undo history.
XCF files are supported in other image editors, yet due to how often the XCF format is revised, it isn’t recommended for use as a data interchange format. On a side note, the name XCF honors the Gimp's origin at the eXperimental Computing Facility of the University of California at Berkeley.
MIME type: image/x-xcf
Learn more about .XCF files:
Visit the Gimp web page.
Learn about Images at ITKnowledgeExchange.com.