Appears to be the best classic open source roguelike of the 2020's.

This website is really cool! crawl.akrasiac.org:8080/#lobby You can spectate players live and chat! Also has statistics.

Devs of this game are smart, they have one good in-tree tileset, unlike some other text-based games that didn't have an in-tree option...

Build on Ubuntu 21.10:

sudo apt install build-essential libncursesw5-dev bison flex liblua5.1-0-dev \
libsqlite3-dev libz-dev pkg-config python3-yaml binutils-gold python-is-python3 \
libsdl2-image-dev libsdl2-mixer-dev libsdl2-dev libfreetype6-dev libpng-dev \
fonts-dejavu-core advancecomp pngcrush

git clone --depth 1 --branch 0.28.0 https://github.com/crawl/crawl
cd crawl/crawl-ref/source
echo 0.28-a > util/release_ver
make -j`nproc` TILES=y
./crawl

This launches the UI version already for you.