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Lozza,
a JavaScript open source chess engine and user interface by Colin Jenkins, first introduced in March 2014, licensed under the GPL v3.0. To play a game of chess or to analyze a position via FEN online, Lozza requires a modern web browser since it is instantiated as web worker. As UCI engine, Lozza can be used in Windows GUIs like WinBoard or Arena via Edmund Moshammer's jsUCI tool starting with jsuci.exe lozza.js ^{1 2}. Other JavaScript based UCI engines, also source-to-source compiled to JavaScript, are able to run under Lozza's web based user interface ³, for instance the Emscripten port of Stockfish 5, Stockfish-js ⁴.

Description

Lozza represents the board using a 12x12 mailbox array and lists of white and black pieces. The principal variation search inside the classical iterative deepening framework features a transposition table indexed by Zobrist keys and state of the art selectivity, amongst others null move pruning, late move reductions, and IID. It has implemented the simplified evaluation function by Tomasz Michniewski ^{5 6}.

Forum Posts

2014

• Lozza - A javascript UI and engine by Colin Jenkins, CCC, March 01, 2014
• Javascript chess engine using simplified eval by Colin Jenkins, CCC, September 13, 2014
• Lozza - a Javascript web based UCI engine - update v1.10 by Colin Jenkins, CCC, October 18, 2014

2015 ...

• Stockfish in Lozza UIs by Colin Jenkins, CCC, January 07, 2015 » Stockfish
• Lozza - A Javascript Engine - version 1.14 by Colin Jenkins, CCC, January 25, 2015
• Lozza website updated to 1.15 by Colin Jenkins, CCC, April 24, 2015
• Lozza 1.16 by Colin Jenkins, CCC, October 31, 2015
• Lozza (web based) UI tweaks by Colin Jenkins, CCC, February 26, 2016
• Lozza v1.17 release by Colin Jenkins, CCC, July 29, 2016
• How to go about chasing a bug like this? by Colin Jenkins, CCC, February 09, 2017
• Lozza 1.18 by Colin Jenkins, CCC, April 17, 2018
• github pages by Colin Jenkins, CCC, March 07, 2019

2020 ...

• Lozza 2.0 by Colin Jenkins, CCC, February 18, 2021
• Lozza on Lichess with a daily 'style' by Colin Jenkins, CCC, January 28, 2022
• Re: New engine releases & news H1 2022 (Lozza 2.2) by Colin Jenkins, CCC, March 12, 2022

External Links

Chess Engine

• GitHub - op12no2/lozza: A simple Javascript UCI chess engine
• Lozza - javascript chess engine

Lozza - javascript chess engine - Help

lozza.js

• Lozza in CCRL 40/40

Lozza UI

• GitHub - op12no2/lozza-ui: Web UIs for the Lozza chess engine
• Play Lozza online

Misc

• Lozza from Wikipedia
• Urban Dictionary: Lozza

References