PlainDSP Open source , free or is purchase necessary ?

Before I get too far cutting and pasting PlainADC.
I understand there is now a combined library PlainDSP ( PlainFFT and PlainADC);
I have the PlainFFT working.
But the references while downloading PlainADC leads me to believe that to get COMPLETE library, whatever the name it is, one needs to PURCHASE some kits to get PlainDSP.
I looks as both PlainFFT and PlainADC are "open" source , but PlainDSP is not.
Am I correct ?
Cheers Vaclav

PS Please don't ask why I am getting these libraries.