The Affero GPL is baffling, and iText's use of it is even more so.
There is surprisingly little data about this license and its effects,
and it doesn't give me a warm and fuzzy feeling.
Affero is meant to prevent people from using GPL code on their servers
which provide network services of some sort (like SOAP or ASP or
whatnot) for other systems. Such servers must provide the source to
their code via HTTP I think. But it's written so broadly that it's
hard to tell whether this applies in other situations. For example,
if you offer a MASON applet over the web, and even offer the code on
your web page, are you still required to have a facility on your
applet to serve its own source code to people who want it? This would
depend on whether or not the original iText source offered such a
facility. But you're required to find that out, which so far as I can
tell means scouring their source.
Why in the world iText is using this is beyond me.