For distributed cloud computing and big data:
Object Persistence API for Cassandra (OPAC) is an open source high-performance object-relational mapping Java Driver for Cassandra (C*). OPAC enables definition-driven management of C* db objects (schema, table, materialized view and constraint) and provides out-of-the-box zero-code data retrieval, creation, update and deletion (CRUD) functionality for the defined objects. OPAC maximizes performance by utilizing multi-threading for entity relationship building and by retrieving only the minimally required columns of the intermediate entities. OPAC is built on top of DataStax Java Driver. OPAC is released under open-source FreeBSD license and is free for commercial use.
Object Flows is a fully customizable Java workflow engine and state-machine. With no transaction commit/rollback capabilities in C*, a state-machine provides a best possible technique to achieve eventual data consistency in a distributed environment. Object Flows state machine ensures that a requested state for e.g. update activity status to Successful after an email is successfully sent, is achieved as soon as possible and automatically retried upon any system errors or reported for manual resolution upon any data errors. Object Flows is a perfect fit for any scenario involving organizational hierarchy, business process models, security, and automated task execution such as messaging. Object Flows also provides out-of-the-box integration with third-party APIs such as Maps, SMS, Email, and iOS and Android device messaging. Object Flows is built using Ohioedge 2.0 – a linearly scalable, no single point of failure architecture.
Kabuter is a simple group messaging and event notification app! Kabuter is entirely built using OPAC and uses Object Flow state-machine for asynchronous state management of objects/data.