Best of all, it is FREE! You can learn more about LibreOffice 6 and download it here. LibreOffice is available in versions for Windows, MacOS and some forms of Linux. In addition it has DRAW for creating vector graphics and other artwork and MATH for editing mathematical formulas. It contains the traditional features of a word processor, spreadsheet and presentation module (Word, Excel and PowerPoint functions) and an Access-like database. LibreOffice 6 is an open source competitor to the Microsoft Office Suite. However, if you only need to occasionally modify a pdf document, there is a free open source solution available to you. Have you ever wanted to add an image, a signature, delete or add a page to a pdf file? You can do that with software such as Adobe Acrobat DC ($12.99/month) PDF Pen (mac $74.99) and PDF Expert (mac $59.99), all great software if you do a lot of pdf editing.
