LibreOffice - Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.
Kissflow - Kissflow is a workflow tool & business process workflow management software to automate your workflow process. Rated #1 cloud workflow software in Google Apps Marketplace.
ONLYOFFICE - ONLYOFFICE is a complete office and productivity suite.
Pipefy - Pipefy is a process management software that empowers anyone to create and automate efficient workflows on their own without code.
Apache OpenOffice - Apache OpenOffice is an open source, office document productivity suite.
Process Street - Create beautiful rich process documents in a simple to follow checklist format. Fast, free and incredibly simple to use.