The most popular bridge software on the market. You can play against the computer or against other Bridge Baron owners. It has 7 Bidding SystemsStandard American 5-card Majors, SAYC (Standard Yellow Card), 2-over-1, Precision, Acol, La Majeure Cinquieme, Forum D. BRIDGE BARON ONLINE FEATURES: Play Duplicate/Rubber bridge games; on Mac join tournament tables hosted on iPad/iPhone. Play on Public or Private (invitation) tables. Never wait for seats to fill p; bots will play until humans show upBuild your own Buddy list. Undo and Claim with approval from other playersChoose convention card for each partnership. Bots can be Beginner, Intermediate or Advanced. SYSTEM REQUIREMENTS: Windows: 2000 / XP / Vista / 7 / 8 (English, Francais, Deutsch) To use online play must have Windows XP (SP3) or later. Mac: (English, Francais, Deutsch) Universal Mac OS X application, requires OS X 10.5 or later.