In-Memory Data Grid
An in-memory data grid (IMDG) is an extended distributed cache that features compute capabilities as opposed to simply data storage. In general, IMDGs is a term used by commercial vendors to distinguish themselves from supposedly simpler open source alternatives. [ More ]
Hazelcast: Hazelcast is a commercial (support & premium features) but otherwise open source IMDG written in Java that differentiates itself from the likes of Redis in terms of in-grid computational capabilities and advanced sharding and replication mechanisms as well as special focus on making redundant other glue messaging solutions.
Oracle Coherence: Oracle Coherence was one of the first big vendor caching solutions that made the IMDG concept popular. It is, arguably, a product neglected by Oracle and is often seen as a legacy product for which a migration strategy is recommended.
Apache Ignite: Apache Ignite is an up and coming open source IMDG whose key differentiating aspec is that it can act as a regular SQL database using standard JDBC/ODBC/.NET drivers.