Symple plugin to loop each line of text.
mt:LinesLoop splits text to each lines and loop them.
<mt:LinesLoop tag="MULTI_LINES_CUSTOM_FIELD">
<mt:LinesLoopHeader><ul></mt:LinesLoopHeader>
<li><mt:LinesLoopLine /></li>
<mt:LinesLoopFooter></ul></mt:LinesLoopFooter>
</mt:LinesLoop>
'name' modifier refers template variable.
<mt:LinesLoop name="MULTI_LINES_VAR">
....
</mt:LinesLoop>
mt:LinesLoop ignores blank line. To include blank lines, set blank modifier.
<mt:LinesLoop blank="1" tag="MULTI_LINES_CUSTOM_FIELD">
<!-- including blank lines -->
</mt:LinesLoop>