Any good PDF Editors out there? (Free)

Personally I have Acrobat Pro so not a problem but have a friend who would rather not pay for that.

Is there a (legally) free PDF Editor out there that is decent and avoids watermarks or limitations (like one page at a time) or ads and so on?

Someone suggested that Open Office has built in PDF editing functionality. Dunno if that is true or not.

Note I need an Editor. Not a Reader or Converter or Creator.

Thanks in advance!

OpenOffice does have it.

So does Foxit, but it puts a little stamp mark on it unless you pay. Not a big deal, but worth knowing.