Hi Lestroso,
It is a goal to have Emscripten support working out of the box in the master branch for the release we hope to have ready by the end of May. It may still require more than the click of a button to ensure your app works with it, but we'll try to make things as easy as possible with clear instructions / tutorials!
In the meantime you can try out the shaders branch:
https://github.com/ecere/ecere-sdk/tree/shaders
This should compile and work with Emscripten/
You will need to use the Emscripten configuration of the ecere.epj project file, and you can try out for example samples/games/chess which has an Emscripten configuration as well.
You will need to set up the Emscripten compiler as well.
I attach a sample configuration you can use for setting up the Emscripten compiler in the IDE.
You can either enter the information in the IDE's Global Settings dialog, or you can add the section to your Windows user's directory's ecereIDE.ini or on Linux ~/.ecereIDErc .
Regards,
-Jerome