Static analysis software for Fortran

I started with the list of Fortran tools on fortran.com:

• ftncheck. A free, static analyser for Fortran 77 programs only, though there is an effort underway to update ftnchek for Fortran 90.
• Forcheck. Not free. Apparently the oldest and most comprehensive static analysis tool. Can handle up to Fortran 95 and some Fortran 2003. There is a trial offered.
  
• Cleanscape FortranLint. Not free. Can handle up to Fortran 95. Interestingly, there is a testimonial for it from NCAR. A trial version is also offered.
• PlusFORT. Not free. The folks that make this, Polyhedron Software, also distribute Forcheck.
  
• Understand 2.0. This isn't in the same class as the others, as it only computes code metrics. It also does some nifty code visualisations. A trial version is available. I fed it the ModelE code months ago, and it seemed to handle it without trouble.

There are also many projects referenced that are now defunct as far as I can tell:

• QA-FORTRAN from Programming Research Ltd. This is the software Les Hatton used in his T Experiments paper.
  
• Forwarn, from Quibus.
  
• FOR_STUDY from Cobalt-Blue.

I also came across a 1999 technical report from Council for the Central Laboratory of the Research Councils (now Science and Technology Facilities Council) that summarises the tools available then and lists their static analysis features. Much of this is still useful.

Note: these are all separate analysis tools. I didn't look at the analysis that the various Fortran compilers can do. Polyhedron Software has a very detailed looking comparison chart.

tl;dr: Forcheck, Cleanscape FortranLint.