**Fortran 90** was a major revision to FORTRAN 77. It introduced many new features and, although it didn't delete any features, several were identified as “obsolescent.”

The full text of the Fortran 90 standard is available in PDF format here from Fortran Standards Work Group JTC1/SC22/WG5: https://wg5-fortran.org/N001-N1100/N692.pdf

• Free form layout | Free form source input.
• Dynamic memory allocation via the `allocatable` attribute and the `allocate` and `deallocate` statements.
• Fortran Module

• Namelist input

None.