Moving the kernel to modern C

You just admitted yourself in another comment that "using C++ is not a technical problem". The problem is the social problem of making sure the C++ code really is smaller and more efficient than the C macros it replaces.

AND THERE ARE TOO MANY "OOH NEW SHINY" LEMMINGS...

Likewise moving away from email - the problem is a social problem - there AREN'T ENOUGH DEVELOPERS. I think a fair few subsystems ARE developed using solutions like github, gitlab, whatever. If it really worked, surely that model would spread rapidly. But it's not working, and it's not "not working" because the solution is better or worse, it's not working because there aren't enough people to make either solution work.

And actually, probably one of the biggest problems with C++, is that IT'S NOT TRANSPARENT. Developers don't have a clear model in their mind of HOW it works. I come from the days when tomorrow's weather forecast took a day to run on the most powerful computers if you were lucky! If you can't model performance down to the bare metal, you have no clue how long the program is going to take to run. That's one of the reasons the kernel has held back on compilers so long, the disconnect between engineering reality and theoretical correctness.

That's one of the reasons I rant about relational. With Pick the database is transparent - as an application developer I can REASON about performance right through to the OS. That's what's so hard with C++ - the devs can NOT reason through to the hardware. (Okay, it's getting harder even with C, but it's not obfuscated ...)

Cheers,
Wol