following a lot of confusion about the state of pdftex on ctan, most of it arising from problems in areas beyond the control of the ctan team, it has been decided that ctan will no longer hold a pdftex directory on the main tree. (the pre-existing pdftex directory has been moved to obsolete/systems/pdftex.)
the sources of pdftex are available in a number of alternative places:
as a pdftex source archive:
systems/web2c -- which has been brought up to date after a long hiatus
as part of a complete distribution source archive:
systems/texlive/Source - a new directory containing compressed archives of the latest state of the texlive discs; this is a *new* directory systems/unix/teTeX-beta - the latest teTeX snapshot (note, at the time this beta is finally released, the source will become systems/unix/teTeX)
while this means that there's no headline directory containing pdftex, the ctan team consider that the situation that we now have consistent, maintained, copies of the source more satisfactory.
Robin Fairbairns
For the CTAN team