IronPDF - SDK for creating and editing PDFs.
PDF Clown - PDF Clown is an open-source general-purpose library for manipulating PDF documents through multiple abstraction layers, rigorously adhering to PDF 1.7 Specification
Aspose.PDF for Java - Aspose.Pdf is a Java PDF component to create PDF documents without using https://alternativeto.
Document .Net - Gives you API to do everything with a document in PDF, DOCX, DOC, RTF, HTML and Text formats.
Tcpdf - TCPDF: Open Source PHP Class for generating PDF documents
PDFSharp - Office & Productivity and Development