Yes, aftermarket electric assistance. I works well when there's no other option but there is a big downside (even more so in the V8).
The power box as well is providing servo assistance also is far higher geared meaning you no longer have to twirl the wheel so much. This is a big factor in a P6 not feeling as modern and agile as more recent cars. IMHO the factory PAS is a far better option if you can make it to work which admittedly is not as easy in the 4 cyl car. The 4 pot is 3.9 turns lock to lock, the V8 4.5 turn and the PAS box is 3.25. That's a massive difference.
By way of reference, it's 2.7 on the SD1 and on a Golf VI 2.6, which is one reason an SD1 feels more modern than a P6 despite the simpler mechanics.
On the plus side, electric assistance is far more efficient - it only draws current while working rather than pumping fluid all the time - which is why modern vehicle use electric systems for economy - they are also lighter, more compact and easier to package.