Instant Messaging is getting more and more popular. Most people have more than one account somewhere and experience the same problems all the time. There are different applications for instant messaging either at home and at school, in the office or at some internet-cafe. Something is always missing and somehow this is getting frustrating fast. That's why we developed mabber. We offer Instant Messaging based on the Jabber/XMPP standard, either web-based and as a mobile application. If you like, you can also download a third-party jabber-application and use our service that way. It doesn't matter how and where you use the service, you can always talk to all your contacts any time. We use open standards and offer our customers the most possible flexibility. mabber makes Instant Messaging even more simple and more useful. We developed a mobile application that lets you chat and send messages whereever you are. Required is a recent mobile phone equipped with Java and some sort of data-plan. We estimate that 1 kb of data allows for about 7 messages. That makes it less expensive than SMS.