C Collection of code snippets by Arne Vajhøj 
C (from articles on eksperten.dk / vajhoej.dk written sometime between 2004 and now) 
      PROGRAM LOOPS
      INTEGER*4 I
      DO 100 I=1,5
        WRITE(*,*) I
100   CONTINUE
      DO 200 I=1,5,2
        WRITE(*,*) I
200   CONTINUE
      I=1
      DO WHILE(I.LE.5)
        WRITE(*,*) I
        I=I+2
      ENDDO
      END