The Qt Company will offer the upcoming main version 6 of the framework for cross-platform development for commercial customers only as a subscription model. This puts companies that use or even offer software on the basis of a commercial Qt license into an unsafe situation: They are only allowed to use or sell it for as long as they have a valid subscription.

The reference to the planned change came from a Heise reader who works for such a company. Qt has probably informed all customers about the change in an email, which can also be seen on the web, but has so far been under the radar of the many messages in the Qt blog about the upcoming release.

One less commercial model The Qt Company informed your customers with the usual reference to the advantages that the subscription model had over the Pepetual License , including a bonus for those who switch to the subscription before the end of the year.

The mailing offers additional advantages to those who make quick decisions .

The reader described the dilemma in which his company and other Qt customers find themselves. There are currently three options for using software developed with the framework: the subscription, a perpetual license and the open source approach with the GNU Lesser General Public License (LGPL). The latter model is not applicable for some providers due to complex requirements. In addition, the Qt Company announced at the beginning of the year that it would no longer offer LTS (Long-Term Support) variants for open source versions. In April, the KDE community also pointed out a planned change that could delay open source releases by up to twelve months compared to commercial ones.

The comparison of commercial licenses is, as is often the case, one A question of weighing up: The subscription model offers regular updates and is initially cheaper, but the perpetual license is more future-proof. Therefore, the reader’s company had decided on the latter.

New dependency The Qt Company is not alone in switching to a subscription-only model: Microsoft is pushing appropriate models, and the tool manufacturer JetBrains switched completely to selling subscriptions five years ago. With Qt, however, there is an essential difference: If you no longer have an Office package or a development environment under license, you only have to ensure in good time that the content can still be used. Then, for example, the texts in LibreOffice or the source code in Visual Studio Code can be edited.

For the Qt However, software developed under the framework is clearly stated in the specifications for the subscription: “If the subscription expires, the customer has no access to use or distribute commercial software that was developed with Qt”. The situation is different for the Perpetual LIcense: “You can continue to use the product forever after the maintenance contract expires” is stated in the associated FAQ entry – with the exception that Qt does not guarantee the support of the purchased items Version there. In the same entry there is the additional note that a subscription license is required for access to Qt 6.

Uncertain future In May, Qt 5. 15 is the last LTS release of the 5 series Series of Qt released. At the same time, it was the first that LTS only offers commercial customers for whom support is still running until 2023. The upcoming Qt 6, for which the first beta was released in October, brings numerous innovations that commercial providers hardly want to withhold from their customers of the company: “Qt could effectively make the subscription so expensive that it is not possible for us to use our software (which was created with Qt),” he wrote in his email. To this end, he cites the case, which from his point of view is very improbable but not impossible, that Qt would be prohibited from selling the framework to his company due to export restrictions.

His company will probably refrain from making the switch because the business risk is too high. This means that Qt 5 will remain if there are actually no permanent licenses for Qt 6. This means that upcoming APIs or additional operating systems are obsolete if they are only supported by the upcoming Qt release.

(rme)