Statement regarding the community project Z-Push

October 20, 2022

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Categories: blog, Featured, Open Source, Z-Push
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Statement regarding the community project Z-Push

As more and more people have noticed, it has become quieter around Z-Push – which can be seen in various places. The core developers are no longer reacting to forums or code commits of the community and the last release was already a while ago. Of course, all of this has a reason that we want to describe below, as well as the consequences.

The relation between Z-Push and Kopano as a company

With the help of Zarafa, Z-Push was launched as an open source community project. Kopano (and previously Zarafa) was the greatest supporter of the community project, as well as user of the technology. However, Z-Push does not belong to the company, it has always been and still is a community project.

Status Quo of Z-Push as a community project

By now Z-Push is around 15 years old. In addition to Zarafa and Kopano, other developers have also written backends for Z-Push and even used it with competing products (which speaks very much for Z-Push as such). As a very specific technology component, Z-Push has achieved a certain degree of distribution over time.

Unfortunately, the main developers decided to devote themselves to other topics and no longer focus on Z-Push – which is more than understandable after 15 years.

The absence of the main developers currently leaves a vacuum that is not easy to fill. As a company, we cannot assess whether and when the main developers themselves intend a continuation of the project.

Status Quo of Z-Push from a technical perspective

The source code has undergone many iteration over the course of approximately 15 years and has been adapted several times to the applicable conventions of the PHP language. Z-Push currently requires PHP version 7.4.

Operating the current Z-Push version can be carried out for years with a corresponding long-term support for PHP 7.4 of a Linux distribution. The medium-term operation of Z-Push is thus ensured. Kopano Groupware currently also requires PHP 7.4 (cf. previous blog post).

Z-Push is not yet compatible with the latest PHP versions 8.x. However, we observe that parts of the community are already showing initiative in this direction.

Microsoft’s ActiveSync protocol, to which Z-Push is compatible, has currently reached version 16.2. Z-Push is currently compatible up to version 14.1 of ActiveSync. This covers most functions, but does not offer the very latest features of the protocol.

Is Kopano going to develop Z-Push further and to rely on it for future products?

No. Kopano as a company will not develop Z-Push any further without the original main developers. In particular, this means that Kopano will not port Z-Push to PHP 8.x and will not implement any new features.

As written above, the code is already around 15 years old, which (among other things) has limitations in the area of maintenance and expansion. Furthermore, the way PHP is being used (meaning design aspects) is based on older paradigms and methods, which provides further limitations in the area of performance and scalability. This is faced by an increasingly intensive use of mobile devices and increasing load on affected interfaces.

In order to implement further functions into the old code, other/new developers would have to familiarize themselves with it first – they would require an extensive work in to get started on an now dated code base. In view of the current situation, the effort required (from an business and technical point of view) does not make sense.

It was therefore decided to no longer rely on Z-Push for future products, to develop a more modern alternative to Z-Push and to implement it directly into new products, so that the performance potential and thus scalability are increased.

Which effects does this currently have for customers of Kopano?

Nothing changes for customers at first – they will continue to receive support for Z-Push as part of the Kopano Groupware subscription. As explained above, nothing stands in the way of an operation of Z-Push in its current form for the coming years.

The future of Z-Push

This is currently in the hands of the open source community. Since we (as a company) cannot simply determine without the main developers what happens to the project as such, we advise the community members who are interested in continuing the project to adjust to this situation and to step in.

The bottom line is that this means nothing else than that we advise the community members to carry out a fork of the code and convert it into a new project structure in order to reorganize themselves there. There are currently no plans to take any resources (e.g. in the form of wiki and code) offline at short notice, so that such a transit should be possible in a reasonable time frame.

If someone is seriously interested in undertaking such an effort, we can provide a little assitance, f.e. in terms of repository cloning. What we certainly cannot do is extract information of our internal bug / support issue tracking system, as there might be sensitive information of customers involved, which of course cannot be shared. Please contact us via if you are seriously interested.