[a] Elvin clients subscribe to events using a language that resembles C boolean expressions.
[b] For example: This expression selects messages that have a field named Department with a string value matching "IT" and a Percent-Disk-Free field with an integer value less than or equal to 10.
In order to achieve these goals it does not provide persistence, durability or guaranteed delivery.
[1] Elvin can thought of as providing a middle ground between low-level network multicast and higher-level, more complex, event brokers such as JMS.
In November 2006, Mantara announced that it would be ceasing to support Elvin as a standalone commercial product by the end of 2007.