Anything below tools is system dependent. On my work machine I might be forced to Ubuntu while on my laptop I'm free to use KDE, or I cannot install my favorite grep clone system-wide on my workstation.
Apart from that we have rather sane defaults that work everywhere (except maybe terminal_cmd).
I would make a PR migrating these to session.conf
``` [tools] make_cmd=make browser_cmd= grep_cmd=grep terminal_cmd=gnome-terminal -e "/bin/sh %c"