Suggestion for how to install both VCL and FMX versions.

[rbwinst-usgs]

BeepButton.zip
BeepButtonExample.zip
You mention that one of the things that isn't working is "installing package for both VCL and FMX in the same time." I have attached an example of a simple component that has both VCL and FMX versions that can be installed simultaneously and example programs that use them. The component itself is worthless. It is just a button that beeps when you click it. Nevertheless, it does demonstrate how VCL and FMX versions of a component can both be installed.
One unsolved problem is how to have the component automatically detect whether it is in a VCL or FMX program. For the examples, the user use to define "FmxBeepButton" in FMX programs.

[livius2]

I know that by using different unit names, I can do this. However, we need to have the same unit names, like VirtualTrees.pas, not FMX.VirtualTrees.pas. If we can't find a way to achieve this, we will probably end up with the scenario mentioned above.

and remember about debugging such scenario :(