Current commercial Qt developer on iMX6 here.<p>You can use the LGPL version of Qt as long as you use dynamic linking to the Qt libraries and provide for the other things in the agreement (like letting users access the Qt source code, provide a way to update libs, etc).  I haven&#x27;t had a need to modify the libraries at all, I&#x27;m using a vanilla build for ARM right from the Yocto output.<p>In my opinion (been doing this for 25 years) Qt is the only embedded UI that&#x27;s worth using these days.  I stick with 4.8 and don&#x27;t use Qt5 or QML, although you probably get a lot more performance out of the system that way and get to harness the accelerator under OpenGL.<p>Qt4 on 6Solo works fine enough for me and it&#x27;s dead simple to do stuff like talk to lower-level drivers or make a Windows version for demonstration.  Freescale supports enough of the backend stuff to use gStreamer and ALSA.  I like that.<p>I recently tore down a car infotainment system that used iMX6 and Opera as the UI.  The backend was all in Javascript.  It looks like hell to develop for, but then again I don&#x27;t work in Javascript all day.