Has anyone done anything with this? Looking to get going with it and any advice on it would be cool
I’ve not used it myself, but I’ve just taken a look at it. It seems to have some sensible ideas, the OTA stuff isn’t entirely crazy, and the content is at least open. Sadly there’s a CLA which puts me off using it because it hints at Cesenta intending to do evil later, which doesn’t make me happy. It might just be the dual-licence nature of it but frankly making it ISC or BSD licence instead of dual commercial/GPLv2 would have solved that without the need of a nasty CLA.
The code itself isn’t pretty, and seems to lack in-code documentation, but the website docs seem well written if potentially incomplete.
I’d say that over-all it’s worth a look-see on a device, but if you do develop something with it; I’d strongly recommend forking the repo to ensure that you keep a reliable copy of the code in case they do something daft.
D.
What do you mean by CLA?
My ignorance of licenses is showing here, all I can see is in theory you’d have to open source your code if you use it, or am I missing something?
I’m tempted to give it a shot, their JS example appeals to me (being a JS dev - I respect that’s not everyones flavour https://github.com/mongoose-os-apps/demo-js/blob/master/fs/init.js)
They support the nodeMCU (https://mongoose-os.com/docs/reference/supported-hardware.html) so maybe this could be how the big red button comes back into play 
A CLA is a ‘Contributor Licence Agreement’ which is a legal instrument by which copyright ends up being transferred from contributors to the codebase owner. In general I’m very leery of open source projects which use CLAs because it usually means they want to reserve the right to sell your work in the future, or even to close it all off later. As a free-software person they cause alarm bells.
As I said though, I think it’s worth a look-see on a device, and so long as you keep a full copy of the OS repo in your github (or the space’s) I think it’ll be fine.
D.
Thanks for the explanation.
By “sell your work” presumably this would only apply if you contributed to the core code, or does this mean they could sell what you do with it?
I’ll have a play around with it - some people at work are looking at using it for some IoT innovation stuff so it’ll be interesting to see what their thoughts on licenses are in the context of a big company.
And I’ll keep a fork of the repo just in case things go nuclear 