Caissa

Caissa.com is the world's first web-based chess server, and the first with a fully graphical interface. Launched on July 1, 1995 by Caissa Project LLC, it has operated continuously for over 30 years, making it one of the longest-running chess platforms on the internet.

The platform offers free online chess in multiple formats: live (real-time), correspondence (turn-based), Chess960 (Fischer Random), and a custom variant called Apollo Chess. Tournaments run continuously throughout the day in both Swiss and round-robin formats with various time controls. Everything runs in the browser with no downloads or special software required.

Beyond gameplay, Caissa provides a suite of free web-based tools: a PGN Maker for creating and editing game notation files, a Game Viewer with an embeddable graphical interface for stepping through games, and a Diagram Maker that generates high-quality board images with support for animated move sequences.

Caissa is completely free to play. It keeps things intentionally simple, focusing on the core chess experience rather than social features or AI coaching. For players who appreciate chess history or want a no-frills platform, Caissa is the server that started it all.