  We describe 14 years of public data from the Parkes Pulsar Timing Array
(PPTA), an ongoing project that is producing precise measurements of pulse
times of arrival from 26 millisecond pulsars using the 64-m Parkes radio
telescope with a cadence of approximately three weeks in three observing bands.
A comprehensive description of the pulsar observing systems employed at the
telescope since 2004 is provided, including the calibration methodology and an
analysis of the stability of system components. We attempt to provide full
accounting of the reduction from the raw measured Stokes parameters to pulse
times of arrival to aid third parties in reproducing our results. This
conversion is encapsulated in a processing pipeline designed to track
provenance. Our data products include pulse times of arrival for each of the
pulsars along with an initial set of pulsar parameters and noise models. The
calibrated pulse profiles and timing template profiles are also available.
These data represent almost 21,000 hrs of recorded data spanning over 14 years.
After accounting for processes that induce time-correlated noise, 22 of the
pulsars have weighted root-mean-square timing residuals of < 1 ${\mu}$s in at
least one radio band. The data should allow end users to quickly undertake
their own gravitational-wave analyses (for example) without having to
understand the intricacies of pulsar polarisation calibration or attain a
mastery of radio-frequency interference mitigation as is required when
analysing raw data files.
