File Extension LGP File Format Gnu licency text file LGP stands for Gnu licency text file. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question Sudden Change of File Ext from .doc to .doc.qbk using Polaris Office gzip (GNU zip) Hashing library for c++ ?