GIMP contains default support for PDF format using the File ► Export to.. function so you can that to export GIMP's XCF images as PDF. You can download GIMP for free.
Convert GIMP XCF bitmap image to Adobe Portable document format.
We have found 3 software records in our database eligible for .xcf to .pdf file format conversion.
Microsoft Windows software - convert xcf to pdf on Windows
A free graphics and photo editor and authoring tool
Convert from xcf file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned xcf to pdf. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert xcf to pdf on OS X
Mac version of the popular graphics editor
Linux/Unix software - convert xcf to pdf on Linux
GNU Image Manipulation Program