On a Apple computer, the “Print” function of the “Preview” app includes the choice for printing the open file to PDF. This works for converting various picture formats to PDF. In fact, any open printable file can be printed as a PDF. If your objective is to make a PDF into a searchable PDF, Word To Pdf Conversion works. There are some “free” software listings on the Internet, but I can’t suggest one or another. On a Apple computer, if you just want to merge two or more PDF files, click theft-most icon above the main PDF window. There’s dropdown with several choices. The second is to open “thumbnails”. Click it; you get thumbnails of every slide in your PDF file. Do this with both of the files you want to merge. Drag thumbnails from one file to the other - in the order you choose. You now have the merged file. (This is probably identical in the Windows operating system.) HTH
USE PDF Converter is a Windows-based utility that works with both the standard Microsoft Office and the open source OpenOffice and LibreOffice. To convert .DOC, .DSC, .XLS, .XLSX, .PPT, .PIF, .PSC files to an OpenOffice OpenDocument Format PDF, the software starts with a selection that is marked in red. If you drag any PDF that already has PDF symbols selected, the program will start to add symbols to that PDF too. To add symbols into other documents, right-click the desired file and select ‛PDF Symbols‛ from the context menu. For this to work, the user of the program needs to have Administrator rights. PDF Converters for Linux The best free and open source converter tools are for Windows. On the other hand, there are free and open source options for Linux computers. There are various Linux versions of these tools. On this page, I provide links for some examples of.