This does seem a bit of a limitation. It's 2017 not 1999.
I'm not directly comparing Outsystems with any of the following but: Ionic, Phonegap, Appcelerator, FuseTools, NativeScript, Appery, Screendy, Appgyver... in fact ever mobile dev platform that comes to mind has multi-platform tools either in the native GUI, command line or through a browser. Appery & Screendy have really rich visual IDEs for building apps & wiring up components to REST backends etc. all done in the browser.
Even Microsoft's Xamarin Studio has a Mac version! Yet the OutSystems offering is tied to Windows....so that people can develop apps which run on... Android and iOS?
It's a real shame.
I'm a bit dazed and confused that nobody has posted the comment 'You do know there's a beta version of outsystems that runs in a browser?' I found out by accident when logging into my outsystems account through a web browser and saw the "We notice you're fortunate enough not to be using Windows, do you want to try the limited web beta version?" or something similar. ;-)Amazing news - I wonder how 'limited' the beta is?
The web version as it is today, is very experimental with limited capability. Here's a forum post that explains a bit more.