DataNucleus AccessPlatform is a standards-compliant Java persistence product. It is fully compliant with the JDO1, JDO2, JDO2.1, JDO2.2, JDO3, JPA1, JPA2 and JPA2.1 Java standards, and provides a REST API. It complies with the OGC Simple Feature Spec for persistence of geospatial Java types. It allows access to all popular RDBMS available today, together with the MongoDB, LDAP, NeoDatis, JSON, Excel/ODF spreadsheets, XML, BigTable, HBase, and Neo4j databases.
PersistClass provides access to relational databases for PHP. It attempts to focus on simplicity and convenience by eliminating the need for boilerplate, meaningless code. It can establish database connections (MySQL, Oracle, etc.), execute SQL queries, parse query results, provide convenience methods (read a single row or value, etc.), escape data (against SQL injection, HTML escaping for outputs), handle transactions, and provide strict error handling and object persistence (storing and retrieving PHP objects in db tables).
Objectify-Appengine is a thin Java wrapper around Google App Engine's low-level datastore API that allows you to persist type-safe POJO objects. It provides a human-friendly query interface, generified key, query, and prepared query classes, GWT-able entity objects, and transactions in one lightweight jar file with no dependencies.
Tephlon is an easy PHP persistence library. It has a highly modular OOP design and a no-SQL storage system. It stores any object or variable safely and tidily on disk for fast access. The API is meant to be easy and fast to learn. It features Java-style key-value maps, namespaces, easy Codeigniter integration, programmable lifetime of records, a multi-driver architecture, reliable and well-tested code, and easy incremental backup of data with SVN or GIT.
Athena Framework for Java is a full fledged enterprise object-relational mapping (ORM) framework that employs metadata as mapping configuration. It greatly simplifies Java Web application development by removing the requirement of manual mapping and manual database schema updating. In addition to features like Java object persistence, powerful EJBQL querying execution, and comprehensive code generation, Athena has built-in support for multi-tenancy, which enables developers to build cloud applications easily. Athena can be easily integrated with other libraries like Struts or Spring to provide full stacks of service.
Ujorm is an easy-to-use ORM framework based on key-value objects. The framework was designed for rapid Java development with great performance and a small footprint. The key features are type safe queries, relation mapping by Java code, no entity states, and a memory overloading protection cache.