What are your commonly used PDF SDKs? Why?

Question

I want to learn about some SDKs recently. If you have any trouble, please share your views on the PDF SDKs you have used. You can also use some other PDF SDKs that are not listed!

- ComPDFKit PDF SDK?

- Foxit?

- PDFTron?

- PSPDFKit?

- Datalogics?