Couldn't find the language specification anywhere, it basically the Nix source? The repo's README refers to the Nix manual, but it seems incomplete. For example
copy-elision
arcgis-runtime-net
web-folders
quickform
apple-watch
react-scroll
arena-simulation
phantom-wallet
android-billing
performance-monitor
mailmerge
npgsql
unidac
querydsl
webpack-style-loader
proof-general
wagtail-admin
mobileserviceclient
gitolite
blockui
mixed-integer-programming
population
gmail-pop
rrdtool
text-direction
mayanedms
openpop
shake-build-system
kbuild
ipfs-http-client