  Planetary nebulae (PNe) were expected to be filled with hot pressurized gas
driving their expansion. ROSAT hinted at the presence of diffuse X-ray emission
from these hot bubbles and detected the first sources of hard X-ray emission
from their central stars, but it was not until the advent of Chandra and
XMM-Newton that we became able to study in detail their occurrence and physical
properties. Here I review the progress in the X-ray observations of PNe since
the first WORKshop for PLAnetary Nebulae observationS (WORKPLANS) and present
the perspective for future X-ray missions with particular emphasis on eROSITA.
