What is this?
Lichess (lila) is the free, adless and open source online chess server behind lichess.org, focused on realtime play and ease of use.
Lichess (lila) is the free, adless and open source online chess server behind lichess.org, focused on realtime play and ease of use.Is this the lichess.org website itself, or a library I plug into my own app?It is the actual server code that powers lichess.org — a complete realtime chess server, not a library. The pure chess rules it relies on live in a separate scalachess submodule.
It is the actual server code that powers lichess.org — a complete realtime chess server, not a library. The pure chess rules it relies on live in a separate scalachess submodule.Can I run my own copy of it?There is no quick install: the Wiki describes how to set up a full development environment, and the build toolchain expects Node 24+ and pnpm 12+.
There is no quick install: the Wiki describes how to set up a full development environment, and the build toolchain expects Node 24+ and pnpm 12+.Will it work in my browser?Only current browsers: Firefox 115+ (recommended), Chrome 112+, Edge 111+, Opera 97+ or Safari 16.2+. Anything older will not work.
Only current browsers: Firefox 115+ (recommended), Chrome 112+, Edge 111+, Opera 97+ or Safari 16.2+. Anything older will not work.Is the code really free to use, or is there a catch?GNU Affero GPL 3 or any later version, at your choice — a strong copyleft license that fits its forever-free, non-profit mission.
GNU Affero GPL 3 or any later version, at your choice — a strong copyleft license that fits its forever-free, non-profit mission.Why is everything free? Who pays for it?Lichess is run as a non-profit, and forever free, adless and open source is the whole point of the project. Even the analysis cluster runs on donated servers.
Lichess is run as a non-profit, and forever free, adless and open source is the whole point of the project. Even the analysis cluster runs on donated servers.How many languages does the site come in?More than 140, thanks to the community translating Lichess through Crowdin.
More than 140, thanks to the community translating Lichess through Crowdin.How do live moves reach my opponent so fast?Realtime play runs over WebSockets, which are handled by a separate dedicated server that communicates with the main one through Redis.
Realtime play runs over WebSockets, which are handled by a separate dedicated server that communicates with the main one through Redis.What are similar projects?fp-ts, mall-swarm, server, rankme.fast, mall-learning, sails, azerioid-stack-manager, platform
fp-ts, mall-swarm, server, rankme.fast, mall-learning, sails, azerioid-stack-manager, platformWhich topics is it in?free-software, cluster, type-safe, analysis, scala, sass, multiplayer, nginx, functional-programming, elasticsearch, realtime, training
free-software, cluster, type-safe, analysis, scala, sass, multiplayer, nginx, functional-programming, elasticsearch, realtime, training