(Almost) all GNU programs ship info documentation that is viewable with info <topic>. This uses a TUI for displaying the documentation. I dislike this, since it is hardly readable. Given the .texi-files, on can also generate a pdf-file from the documentation, but this makes it neccessary to manually download the source package. Is there a way to generate pdf-documentation from the .info-files?
Please move this question to superuser.com if appropriate.
You could use other readers like tkinfo or pinfo. Or just use your browser going to https://gnu.org/software/program-name. I haven't found nothing to convert info files to pdf.