A GDE file is a document created by The Guide, a free Windows program used to create documents that are organized in a hierarchical, tree-like structure. It contains one or more pages, which may include rich text with fonts or colors, hyperlinks, and icons. GDE files are often used for saving reports, books, guides, and notes.

GDE file open in The Guide 2 GDE documents, or "guides," are the main file type associated with The Guide, similar to how .DOCX files are supported by Microsoft Word. You most likely will only encounter a GDE document if you are a Windows user and have created a document with The Guide. You may also receive a GDE file from a co-worker or friend who uses The Guide to compose documents. To create a new document with The Guide, select File → New, modify the document, then select File → Save or Save As.... To open a GDE file with The Guide, select File → Open.... To export a document as an .RTF file with The Guide, select File → Export.... NOTE: GDE documents are rather obscure since The Guide is not widely used and not actively developed.