Callas was founded 30 years ago and is headquartered in Berlin, Germany.

It has more than 4,000 customers worldwide and describes its software as finding “simple ways to handle complex PDF challenges”.

Products include pdfToolbox and pdfaPilot, and it also supplies OEM software that is integrated into other systems.

Adobe, Quark and Xerox are among suppliers that have incorporated Callas tech into their own solutions.

Italy-headquartered Durst is best known for its digital printing systems for a range of industrial applications including large-format, labels and corrugated.

The group also has a Software & Solutions division aimed at optimising printing processes, which includes Lift ERP/MIS and the Smart Shop web-to-print system.

Durst said the acquisition would strengthen its offering and foster industry connectivity.

Callas “will remain autonomous in its management and product development”.

Durst Group CEO and co-owner Christoph Gamper commented: “This is not just another step towards digitalization – we are actively shaping the future of digital printing.

“With Callas at our side, we are making print software smarter, more connected, and more powerful. The best solutions arise when strong partners work together toward a shared vision.”

Callas CEO Dietrich von Seggern said that maintaining Callas' independence “was a central requirement” for joining the Durst Group.

“Our customers must be able to trust that Callas will continue as a reliable partner – while also gaining a new foundation for long-term innovation,” he said.

The terms of the deal were not disclosed.

Durst said that the acquisition would bring long-term security and new technological opportunities for Callas customers and OEM partners. There will be no changes to OEM contracts.

The first major outing for Durst Group and Callas will be the upcoming Fespa Global Print Expo in Berlin, from 6-9 May.