Free open source alternative app list of Microsoft Office :

WPS Office

All-in-one Office Suite for Everyone, Free, Compatible, Shareable.

FreemiumWindowsmacOSLinuxAndroidiOS

Others are looking for free open source alternatives of following apps:

66analytics

Self-hosted web analytics tool that brings good analytics back to you. Simple tracking, heatmaps & session recordings. One-time payment & free lifetime updates.

1Password

A password manager, digital vault, form filler, and secure digital wallet. Manage everything in one secure place – 1Password remembers all your passwords and sensitive information, so you don’t have to.

App Cleaner Uninstaller

App cleaner remover that will help you uninstall apps on your Mac entirely and remove every single trace of them.

Alfred

Alfred is a productivity application for macOS, which boosts your efficiency with hotkeys, keywords and text expansion. Search your Mac and the web, and control your Mac using custom actions with the Powerpack.

ActiveCampaign

Your solution for personalized email marketing, automation, and sales engagement. Automate across your entire marketing stack with 900+ integrations.

Acorn 7

Acorn is an awesome image editor for the Mac. Use Acorn to edit photos, add filters, retouch pictures, paint, crop, add text, create new images, and much more!