And you can share the software without repercussions. Similar to Adobe Acrobat, open-source PDF editors come with different tools for altering PDF files, from adding text to merging pages.

Gimp is normally used to create or manipulate images files, but can also work with PDFs if you understand how it works and what it's limits are.

Word provides all the tools you need to modify PDF text and images, but it may struggle with more complex documents.