Safari prevents Javascript from saving files as a security feature. It does let them open in a new tab. LUTCalc will first try to open a file save dialog. If a browser does not allow this, it will save the file to the browser's designated download folder (usually downloads) and failing that will fall back to opening the file in a new tab. What you have with Safari is the latter case.
If you save that code using Save As and make sure that 'page source' is selected and that you give it a filename ending in .cube, you will have your cube LUT.
Alternatively, I wrote the Mac OS app as a wrapper around the web app to avoid this issue with Safari. The Mac App takes over handling things like file saving and loading, so you can save to particular locations. Unfortunately, it has never been possible to directly save using the online version in Safari.
I've been doing a fair bit of work on LUTCalc lately, in particular completely rewriting the interpolation and extrapolation code for LUT-based colourspaces for speed, accuracy and maintainability. I've also been looking into the presets (in particular Resolve seems to handle automatic clip range setting a little differently since v12).
Hopefully I should be pretty close to uploading it soon as an update. Just trying to make sure I haven't broken anything important! ;-)
