Chess

Chess is a game based on the and distributed by Apple as part of macOS.

Gameplay options
When first launched, the user is presented with an option to download a 1.2 GB library to enable speech recognition. The user can select a variant of Chess gameplay for new games, including:, , , and. Player options include: humans, the computer, and a remote player via Game Center. For games against the computer, the default computation time is 2 seconds, though this can be modified from a minimum of only 1 move ahead, up to a maximum of 256 seconds.

Computation capacity
The computer computation of Chess.app has been known to take up to 98% of CPU bandwidth during the time allocated. This has been observed to cause CPU fans to spin up, even on recent models.

History
Chess.app dates back to NeXTSTEP 1.0, the predecessor to Mac OS X (now known as macOS) which was originally released in September 1989. It was adapted for color in OpenStep and open sourced in the process through the. It was ported to Mac OS X during the early stages of its development in 1999. When it was released as part of Mac OS X 10.0 in March 2001, it was based on the engine for Unix. Gian-Carlo Pascutto is credited for work dating back to 2000. R. Ancelli & M. Duelli were involved in 2002, and Apple Computer (now Apple Inc.) took over development internally since 2003.

Version 3.0, which was released with OS X 10.8 (Mountain Lion), is based on the open source chess engine, released under the. The source code can be downloaded from the about dialog box of the app.