Yahoo Messenger - Chat, Instant message, SMS, Video Call, PC Calls
[Yahoo Messenger for the Web]

Friends are an instant away on Yahoo Messenger for the Web

No download required to IM with friends
Just sign in from your browser to IM with your Yahoo and Windows Live Messenger™ friends
Send text messages (SMS) to mobile phones
Friend not signed on? No problem — send a text message right to their phone for free

System requirements: Internet Explorer 8 or later, Firefox, Chrome, or Safari.