Most people who write texts on their computer and export them to PDF format come across this problem every once in a while: how do I merge two different PDF files?
You might run into this when you have written a term paper and want to attach a fancy cover page to your text or, like me, need to merge all of your documents (cover letter, resume, diplomas, etc.) into one file for a job application via email.
Fear not, help is on the way!
A while ago, I discovered PDFsam (short for PDF Split and Merge), a free open source tool available for Linux, Mac, and Windows. There are two versions, a free basic version, which I use, and an enhanced version with some more features that requires a donation of your choice.
If you just need to glue several PDF files together, split, or rearrange them, the basic version is just fine. Have a look at it, try it out, and donate to the project if you can.