How to print lines between two patterns, inclusive or exclusive (in sed, AWK or Perl)?

Question

I have a file like the following and I would like to print the lines between two given patterns PAT1 and PAT2.

Answer 1

Alternatively:

sed '/START/,/END/!d;//d'

This deletes all lines except for those between and including START and END, then the //d deletes the START and END lines since // causes sed to use the previous patterns.