@ragazzonoioso I took you up on your dare. I figured the most likely candidate for adware from SF would be Windows, so I installed #ReactOS in a VM, downloaded and installed some .exe filles from #sourceforge, and I admit everything looked clean, vanilla, true to upstream.
There *are* a heck of a lot of ads (even with ublock on) on sourceforge.
Sourceforge like Github, as far as I know, isn't open. But it's a place that once had brand recognition and still does serve some stuff I like.