Many thanks Gordon.
Your intervention is very useful to better understand the "philosophy" behind Espruino.
But there are some technical issues, dictated by the different design choices, which at the moment we still can not evaluate and understand the implications.
For example, Espruino is not 100% compatible with ES5/6 but is it really a problem? I think no.
Instead I consider more interesting criticisms like this:
The API of Espruino is less powerful than the API of low.js is, as Espruino does not provide the Node.js API, which would not fit into the smaller microcontrollers. Espruino provides some API calls which mimic Node.js API calls, such as fs.writeFile, but they do not work the same way. fs.writeFile for example is blocking (there does not seem to be any way to write a file asyncronly with Espruino).
Is synchronous writing a big limit (imho yes but sometimes)?
Node.js "porting"? No, thanks. It's cool.... but maybe in the future.
Does not using bytecode have only the slowness of execution as the only side effect? Speed is not a problem in my opinion. (moreover Espruino can compile on official boards...)
While the ram out of memory is a problem.
Working with sockets, json parsing, many variables, bluetooth access, use of different modules, etc ... is better a (a.e) DukTape or Espruino approach? (but then we make a breakthrough and use a Raspberry et similia :D )
These are my/our concerns ... if someone has already experiences/opinions about it is welcome. :D
Obviously my most technical questions will come as we encounter problems :) , for the moment I am asking only an overview to those who have already had the opportunity to use different embedded js engine. ;)
P.S. / Disclaimer
In my team I choose Espruino at now because... it's funny! :)
I like its webide, repl, life cycle of script, community, docs, ...