Well done, thank you Sergey!

We also see EGroupware as an alternative to Microsoft 365. By putting together different components and because we are only a small team, the integration/continuous interface is not the same as with Microsoft, but we offer the users, but also especially the operators/admins of EGroupware a lot more possibilities. This all wants to be discovered!

I have one correction:
You can integrate Collabora Online, not Collabora Office.

Collabora Office is the desktop version (of LibreOffice + long-term support) and Collabora Online is the online version of LibreOffice(Online).

Here are the relevant links:
Collabora Office: https://www.collaboraoffice.com/solutions/collabora-office/
Collabora Online: https://www.collaboraoffice.com/collabora-online/
Our website for this: https://www.egroupware.org/en/online-office
References in our forum to the integration page and my (old) lecture: https://help.egroupware.org/t/de-uk-collabora-neue-integrationsseite-new-integration-page/74715

I would like to add a few points, which mostly go beyond the Microsoft 365 offer:

One can integrate other web applications (under certain conditions). Like we did with Rocket.Chat or Apache Guacamole (Remote Desktop): https://help.egroupware.org/t/uk-kielux-2020-jitsi-and-apache-guacamole-in-egroupware-video-and-presentation-slides/75298

You can develop your own application on the basis of EGroupware and use functions such as user administration, document generation, file storage, sending mail, … with it. There are users who create their business software with it.

With the upcoming version 21.1, EGroupware will get a Kanban board (in the EPL version) and other great functions: https://help.egroupware.org/t/uk-presentation-video-and-slides-lecture-grazer-linux-tage-2021-new-in-egroupware-21-1/75878

EGroupware can be installed as Community-Edition On-Premises or elsewhere. The professional version with some more business functions can also be operated by yourself and we also offer this version as SaaS (from Germany): https://www.egroupware.org/en/pricing

The versions and the operating location can be changed.

If anyone is interested in writing a larger article on EGroupware, I will gladly support you: su@egroupware.org

Some flyers can be downloaded here: https://www.egroupware.org/en/community

For further help and questions please visit our community forum: https://help.egroupware.org

So far for the moment…

Many greetings
Stefan
EGroupware Community Manager