Thanks. I used to be a C++ user when there were no better languages for rapid GUI application development around (C++Builder/Delphi were the best). I've switched to C# with WinForms many years ago. Now I'm going to try Qt5 with Python (just because there is no WinForms designer for Linux, nevertheless Qt Creator doesn't feel as intuitive as C++Builder, VisualBasic and WinForms designer did though I believe it can do the job) but I'm certainly interested in the web GUI world as writing a single app that is going to run on every computer (smartphones included) seamlessly via a web browser feels extremely appealing.