The two largest software clients for Bitcoin nodes, Bitcoin Core and Bitcoin QT, can be pruned.

Bitcoin QT is not a node? It's a frontend?

It's currently single process, containing all three - full node, wallet and Qt GUI.

Ah okay. Didn't know that. But it's running Bitcoin Core inside, right?

Yes, there are two executables you can run for Bitcoin Core - bitcoind, which contains only node and wallet, and bitcoin-qt, which contains node, wallet and GUI.