A few years back, \TEX\ could only produce
\fillinfield [dvi]{\DVI} output,
but nowadays, thanks to \fillinfield {Han The Thanh}, we can also directly produce \fillinfield [pdf] {\PDF}!
Nice eh? Actually, while the first field module was prototyped
in \ACROBAT, the current implementation was debugged in
\fillinfield [pdfTeX] {\PDFTEX}. Field support in \fillinfield
[ConTeXt] {\CONTEXT} is rather advanced and complete and all
kind of fields are supported. One can hook in appearances, and
validation \fillinfield [JavaScripts] {\JAVASCRIPT}’s. Fields
can be cloned and copied, where the latter saves some space. By
using \fillinfield {objects} when suited, this module saves
space anyway.