Run your private office with ZCSPlus

Achieve digital sovereignty in your organization

Why ZCSPlus ?


ZCSPlus integrates Calendar, Contacts, Mail and other productivity features to help teams get their work done faster and easier. Give everyone a self-hosted online office.

OnlyOffice Docs

View, edit, and collaborate on docs, sheets, slides. Build fillable PDF forms and them in online. Read/Edit PDFs, export/import to/from PDF. Convert docs to Markdown and HTML.

Online Talk/Chat

Effortless communication with your colleagues. Screen sharing, meeting recording, waiting room, and moderation. For more dense meetings, you can easily attach Jitsi.

Zextras Suite

Real-Time Backup and Restore, Outlook Sync, Mobile Device Sync (Exchange ActiveSync protocol), Advanced Storage, Multiple authentication methods, Admin delegation.





Email is where collaboration starts.



Helps your businesses stay organized and productive.



Enabling users to efficiently manage, store, share, and edit documents within a secure and centralized platform.



A powerful online editor for text documents, spreadsheets, and presentations.


Chat & Video

A centralized solution for real-time communication, supported by a cloud-based infrastructure.


Zimlets List

You can download and deploy Zimlets from the Repository ZCSPlus.



Stay in control of your data !


Change Logs

Update to benefit from the latest enhancements.


Zextras Suite Installation Guide

This section contains various information ​requirements, configuration details.


Change Logs

Zextras Suite powers up ZCSPlus.


Change Logs

ONLYOFFICE Docs changelog.


Frequently Asked Question

The project stems from a simple observation, to offer a comprehensive and sovereign solution to companies and public administrations that still rely on Microsoft or Google.
The life and health of their activities are hosted by entities that use your data as an economic model.
There are also the bad students of digital sovereignty, who daily criticize the GAFAM but do not reveal their dependencies on these actors (there are many, even too many).

ZCSPlus relies on Zimbra Collaboration Suite FOSS Edition, and extensions (Zimlets) present on their official GitHub repositories:
Other extensions from the Network pack (public download) are also used, but no modifications have been made to circumvent the use of a Zimbra license.

Reverse engineering is expressly protected under copyright law, as long as you got your hands on the product through legal means.

You may not know it, but although the license protects software, it does not necessarily protect its functionality. In the case of France, article L 112-6-1 of the Intellectual Property Code defines the general principles of reverse engineering, and legally authorizes it in certain situations.
Synacor Inc. has been working in this direction for years with, for example, several modifications of OnlyOffice, see Web/Mail services and Libraries (Open-Source).
It's the same for other players like Microsoft, Google, Adobe...

At ZCSPlus, we have taken this same path to offer you the best solution possible.

Of course !
Apart from the Zextras package which is licensed and limited to 30 days of use, the use of ZCSPlus is completely free, we have no constraints on you being able to offer your services through ZCSPlus.

The choice to integrate the Zextras Suite package is not a coincidence, it will allow you to easily migrate your Zimbra version 8.8 or version 9 to ZCSPlus.
No command line, everything is done from the administration interface!

Self-hosting is the quickest and easiest way to legal compliance with a wide variety of regulations. By keeping data on your company servers, there is no need for contracts with other companies or complicated audit processes.

You still have comply with security and compliance requirements demanding you take appropriate security measures.

ZCSPlus is above all a community project without any economic model, we draw our energy from its design and especially from the responsiveness of updates, which already represents a lot of work.
Our goal is to be able to build a community network that can provide you with support and meet your expectations.

You can contact us using this form: Contact
The language barrier is never easy, but if you are from a French-speaking country or speak French, you can reach us by telephone.


This is the first thing we asked ourselves, and trust is not enough to make ZCSPlus reassuring.

In short, we reside in a European country (France) where the law is very clear, the Penal Code punishes "fraudulent access and maintenance in an automated data processing system" with a sentence of three years in prison. and a fine of 100,000 euros according to article 323-1 of the penal code.
Even if you live in another country, a judicial request between two countries is enough to punish us for this act.

We challenge anyone to find even a single breach through Bug Bounty, network data packet monitoring, or, as we quote Reverse engineering “which is simple on Java including even doing a checksum of the files” , you will not find any malicious code from us.
On the other hand, the majority of libraries are downloaded directly from the official Zimbra repository, our repository only contains Zimlets with mainly Javascript, or certain libraries under Java which had to be patched to add new functionalities.