Flpsed is a WYSIWYG pseudo PostScript editor. "Pseudo", because you can't
remove or modify existing elements of a document. Flpsed lets you add
arbitrary text lines to existing PostScript 1 documents. Added lines can later
be reedited 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.