Photran is a Fortran IDE GUI based on Eclipse. It appears Photran may not be developed any more. Consider Visual Studio Code as via extensions it supports most of the Photran features and is very actively developed. Note: the Eclipse version obtained via apt install is usually much too old.

Download and install the current Eclipse version. In this example, “Oxygen” (Eclipse 4.6) was used. Extract and run the Eclipse installer (no sudo needed)

tar xf eclipse-inst-linux64.tar.gz
./eclipse-installer/eclipse-installer

Select “Eclipse for Parallel Application Developers”. It will install into “~/eclipse/parallel-oxygen”. Add t ~/.bash_aliases the line

alias eclipse="$HOME/eclipse/parallel-oxygen/eclipse/eclipse"

Open a new Terminal. Type eclipse to open the Eclipse IDE. From Eclipse IDE, click Help → Install New Software In “work with” pick the currently installed Eclipse version. Uncheck the “hide items that are already installed” Type “fortran” in the search box, and select under Programming Language → “Fortran Development Tools (Photran)” and “Linux Intel Fortran Compiler Support”

Photran install guide