For users who dislike the software-as-a-service (SaaS) subscription model, there are robust third-party PDF editors available for a one-time purchase:

An excellent, free desktop tool for Windows that handles splitting, merging, and basic editing. Foxit PDF Editor (Perpetual License Available):

: Because it has not received security patches for over a decade, Acrobat X is highly vulnerable to modern exploits. Risks of Using GitHub for Serial Numbers

A completely free, full-featured PDF editor that includes text editing, PDF conversion, and form-filling without watermarks.

A serial number is a unique code that is used to activate and validate software, in this case, Adobe Acrobat X Pro. It's a 24-character code that is required to unlock the full features of the software. Without a valid serial number, you won't be able to access the advanced features of Adobe Acrobat X Pro.

: Free software for viewing, signing, collaborating on, and annotating PDF files.