flpsed is a WYSIWYG PostScript2 annotator.  You can't remove or modify
existing elements of a document, but flpsed lets you add arbitrary
text lines to existing PostScript 2 documents.  Added lines can later
be re-edited with flpsed.  Using pdftops, which is part of xpdf one can
convert PDF documents to PostScript and also add text to them.  flpsed
is useful for filling in forms, adding notes etc.  GsWidget is now
part of flpsed.  flpsed is released under the GPL.

Features:
    * Add arbitrary text to existing PostScript documents.
    * Reedit text, that has been added with flpsed.
    * The overall structure of the PostScript document is not
      modified.  flpsed only adds the additional text.
    * Batch processing (no X11 required) to modify tagged text lines
      that have been entered interactively with flpsed before.  This
      is very useful for repeatedly filling in forms.
    * Text lines can be imported from other flpsed-modified documents.
    * Import and export PDF. Therefore it can be used as a PDF editor as well.