Dialpad - Switch is a cloud-based phone system built for Google Apps users.
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.
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs
ONLYOFFICE - ONLYOFFICE is a complete office and productivity suite.
3CX - Hosted PBX with CRM integration and mobile apps
Apache OpenOffice - Apache OpenOffice is an open source, office document productivity suite.