KHTML/WebKit: I don't think the GTK/Gnome folks ever wrote a browser engine. KDevelop: Did the GTK/Gnome folks ever write a significant IDE with a code model? Krita: It's focused on painting/illustration and doesn't directly complete with Gimp. Among artists doing this Krita is likely more popular than Gimp now, since the latter isn't even in the running. (Support for MyPaint brushes is progress on that front, though painters want many other features.)
For KMail/Kontact there's Evolution, but arguably neither ever became really popular if you compare them to, say, Thunderbird.
IIRC, it used to be that even the core Qt libs were GPL (unless you paid for a commercial license), while now most (but still not all) libs are also available under the LGPL.
GTK has always been plain LGPL 2. Nothing scary.
Krita serves their website over https and the download over http from some mirror. Can't find any trace of a hash on their site either.
Gimp is actually overfeatured for what they need, but that was the only thing I found which I could install with a good enough certainty that I won't infect their computer with malware.
EDIT: I mean drawing geometrical stuff. Of course it's good for general drawing.
They are knowingly using this dark pattern to make ad money which is too bad, because as you say the app is really good.
I just remembered that there's also Dia (diagram editor), I might give that one a try.
Filename: Krita-3.0-Alpha-master-e5109c2-x86_64.AppImage
Size: 85M (88670208 bytes)
Last modified: Mon, 11 Apr 2016 07:27:01 GMT (Unix time: 1460359621)
SHA-256 Hash: 5d6574f750a188f67548d965ce6a8abd4d33479bc64f88130e545250e179a0e1
SHA-1 Hash: bf969c7ce56aac754eb84a2123caa9cbf4174884
MD5 Hash: ee0b82e82a98086dccad7f1344888a1cAlso sha1 should be avoided nowadays, but at least it's not md5...
That being said, we have to trust something.
Don't even think about "give me this, this, this, and this; check that it is the right version from a trusted source; make it so!" (PortableApps can do that, so it's demonstrably possible, even on Windows)
Progress? We don't need no steenking progress! Package managers are for lusers who prefer clicky GUIs over Glorious Hard Work and spelunking in the dark corners of the net! (How that ever got pushed as user-friendly?)
At the moment it's however largely a case of Microsoft quietly developing a quite powerful tool and then going out of their way to not tell anybody about it. Microsoft has also not shown any interest in developing and supporting their own general software repo (I guess they don't want to compete with their app store). So we've basically got to wait for third party developers to fill the cap. Fortunately the people behind chocolaty are working on this and have said they'll have something ready by Summer 2016.
It's great if you're forced to used Windows as your development machine.
1. Chocolately (https://chocolatey.org/), which most people don't know about, or
2. The Windows Store, which I hope never catches on.
What's worse is when your One True Package Manager creates a broken package because the packager has no clue what they are doing. Debian and SSH ring any bells? Would using an exe provided by the developers have that problem?