The GNAVI project provides GWindows, a Rapid Application Development framework for Graphical User Interfaces on MS Windows.
The durable Open Source answer to Delphi and Visual Basic.
Alire crate: https://alire.ada.dev/crates/gwindows
Mirror: https://github.com/zertovitch/gwindows
Qt Jambi is the Qt library made available to Java. It is an open source technology aimed at all desktop programmers wanting to write rich GUI clients using the Java language, while at the same time taking advantage of Qt’s power and efficiency.
This system provides printed and cursive handwriting recognition service as a shared library on GNU/Linux/Unix systems.
Until someone writes another client, try the S/HIP:
https://sourceforge.net/projects/ship-project/
The all-in-one solution built to help you stay organised and get more bookings with thousands of connections to online travel agencies (OTAs), resellers and suppliers.