Redline.

About Redline

Redline is a video game for Mac OS X developed by Jonas Echterhoff and published by Ambrosia Software. The game's primary features are its ability to simulate actual racing physics, online play, and support for the addition of third party content via plug-ins. The combination of these features have attracted numerous players and led to the creation of a seasonal racing league. Redline also has several modes of gameplay for those who prefer arcade style physics commonly found in other racing games. The game is now currently obsolete and an error message will be displayed upon opening the application as of OS X Snow Leopard and above. However, a fan-made patch allows the game to run on OS X Mavericks and above, but in single-player modes only.