[racket] Hosting the try-racket REPL.

J Arcane wrote at 09/22/2014 02:54 AM:
> I had not actually heard of Xvfb before now, but that could be a good 
> solution. I balk at using full X11 with only 512MB of RAM, but that 
> could be enough to satisfy the original code's expectations. I will 
> have to experiment with it.

Side comment: I wouldn't worry too much about the memory requirements of 
an X11 server daemon (we used to run X11 and everything else on 16MB 
engineering workstations fine, and universities would sometimes run X on 
4MB workstations with megapixel displays, even without local swap.)

The X11 daemon on my computer right here is using only 3MB virtual 
memory total, and I have some server-intensive apps like Firefox running 
against it, on two heads.

(It's mostly only the modern ``desktop environments'' that tend to be 
bloatware (e.g. even a decade ago with those, the little clock panel 
applet was reporting as 50MB RSS), but a plain X11 server daemon itself 
can be pretty small.  A lot of the early development of the desktop 
environments you're using now was by smart-but-inexperienced 20yos who 
were tossed into the deep end, under 20yo managers who were trying to 
start a company.  With some noteworthy exceptions.  Since then, the 
desktop environments seem to have been evolved by often more-experienced 
people, and improved, but the desktop environments weren't built with 
the great architectures and practices from the start, which tends to be 
a technical and cultural burden for a very long time.  And developers 
have usually been targeting contemporary PC desktop hardware, when 
several gigabytes of RAM can be assumed, except for occasional forays 
into devices that are battery-powered and/or are intended to be 
ultra-cheap to manufacture.)

Neil V.