Scribe is a server for aggregating log data streamed in real time from a large number of servers. It is designed to be scalable, extensible without client-side modification, and robust to failure of the network or any specific machine.
Basically, Scribe is a good way to get large volumes of messages from large numbers of servers. It’s not reliable enough for database transactions, but it works pretty well for things like a News Feed. Scribe will most likely be interesting to developers building large scale communications systems or doing large scale data analysis, though Facebook’s Robert Johnson says Facebook uses Scribe for “over 100 use cases.”