Today, May 1st, 2026, we released version 1.5.1 of our open-source e-invoice viewer Quba.
This version fixes some minor issues, among others in it’s interface switching languages (issue #93), the Mac version (issue #155), in the display of both EN16931 (issue #49) as well as higher profiles like Factur-X Extended (issue #27) and regarding invoice attachments (issue #29).
Thanks to our new sponsor Matthäi Bauunternehmen GmbH & Co. KG (Matthäi construction works). Without sponsors and other contributors this maintenance release, as well as our ambitions for a new major release, would not be possible.
We plan to put Quba 2.0 on a entirely different basis: OpenIndex’s Andreas Rudolph, published the great ZUGFeRD Manager as open source, which can create and validate Factur-X/ZUGFeRD e-invoices.
We just added “Quba”‘s display, i.e. visualize XML, functionality. Feel free to try the windows version of the beta version of Quba 2.0, called Quba 1.9.9 and report any bugs encountered in this repo, indicating the beta. You can currently contribute to the development, or build Mac and Linux versions, via the according forked repo.
With this change, Quba 2 then contains and is able to use Mustangproject functionality directly. This includes Mustangproject’s German and European offline e-invoice validation.
Please note that at the same time Mustangproject is also on a trajectory to also being able to validate e-invoices for the french e-invoicing reform as of September. If you consider to contribute in that domain please feel free to sign up for the according webinar on May 7th.
