docassemble - docassemble is a free, open-source expert system for guided interviews and document assembly.
Plumsail Documents - Document automation software that integrates with your favorite apps to generate documents seamlessly.
Knackly - Generate contracts, emails, or other documents of any complexity by automating your knack for doing...
HotDocs - Template-driven, automated document & form assembly software
DocSpring - DocSpring provides a PDF filling API that makes it easy for programmers to fill out and generate PDF documents.
Woodpecker - Legal document automation for solo & small firms. Simple to use, works in Word, connects to everything.