DdD provides a proprietary combined point of sale (PoS) softwarehardware solution, focusing on the fashion retail industry.
The software will be an ideal fit for K3, which provides and supports software, hosting and managed services to the retail, manufacturing and distribution sectors.
Lars-Olof Norell, chairman of K3, said: "We are very pleased to announce the acquisition of DdD which marks an important step in our strategy to increase sales of products with a significant element of K3-owned IP.
“DdD is a well-established business which has developed a highly attractive, cloud-based software solution for retailers, particularly in the fashion sector.
“This acquisition represents a highly complementary fit, bringing IP and an extensive customer base delivering significant recurring revenues. We also see exciting cross-selling opportunities.
“We look forward to the management team joining the group and are also delighted that our placing to raise £13.5m has been well supported by both existing and new institutional investors.
“We intend to continue to look for complementary bolt-on acquisitions and will further refine our overall offering as we seek to accelerate the group's development."
DdD currently operates in Denmark, Germany, Sweden and Norway and has approximately 2,700 installations across 1,800 stores covering over approximately 750 customers.
Customers include Esprit, the sportswear chain, and Saint Tropez, the women's fashion brand.
DdD currently employs 43 people.