SQLObject is an object-relational mapper, i.e., a library that will wrap your database tables in Python classes and your rows in Python instances. It currently supports MySQL through the 'MySQLdb' package, PostgreSQL through the 'psycopg' package, SQLite, Firebird, MaxDB (SAP DB), MS SQL, and Sybase. It should support Python versions back to 2.4.
MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.
hamsterdb Embedded Storage is an embedded database engine for C/C++, including wrappers for Java, .NET, and Erlang. It supports in-memory databases, very fast database cursors, "record number" databases, ACID transactions, and duplicate keys. hamsterdb is very fast and highly configurable. It compiles and runs on Unix platforms, Linux, Microsoft Windows, and embedded platforms.
SymmetricDS provides file and database synchronization with support for multi-master replication, filtered synchronization, and transformation across the network in a heterogeneous environment. It supports multiple subscribers with one-direction or bi-directional, asynchronous data replication. It uses Web and database technologies to replicate data as a scheduled or near-realtime operation. The software has been designed to scale for a large number of nodes, work across low-bandwidth connections, and withstand periods of network outage. It works with most operating systems, file systems, and databases, including Oracle, MySQL, MariaDB, PostgreSQL, MS SQL Server (including Azure), IBM DB2, H2, HSQLDB, Derby, Firebird, Interbase, Informix, Greenplum, SQLite (including Android), Sybase ASE, and Sybase ASA (SQL Anywhere) databases.
JSX serializes Java objects to XML. You can persist objects, evolve them, and send them over the network and between applications. Your object data becomes human-readable and human-writable. You can test it, search it, profile it, audit it, and edit it with ordinary text and XML tools. JSX handles all POJOs and also all classes that require Java's own object serialization.
TinyButStrong is a template class for PHP that allows you to generate XML/HTML pages and any other files based on text source. The engine gives facilities to work with any databases, including in native PDO, MySQL, PostgreSQL, SQLite, PHP arrays, and more. It is possible to design templates using any visual editor (like Dreamweaver or FrontPage), and thus to make templates that are compatible with W3C standards for example. It features simple block management, useful display formats, conditional displaying for blocks and locators, remote XML/HTML attribute modification, a cache system, and the ability to include sub-templates and execute associated scripts. Plug-ins are supported since version 3.0.
With MetaModel, you use a type-safe SQL-like API for querying any datastore. It is a data access framework providing a common interface for exploration and querying of different types of datastores. It isn't a data mapping framework. Instead, it emphasizes abstraction of metadata and the ability to add data sources at runtime, making MetaModel great for generic data processing applications, but less so for applications modeled around a particular domain.
Libzdb is a database library with thread-safe connection pooling. The library can connect transparently to multiple database systems. It has zero runtime configuration and connections are specified via a URL scheme. A modern object-oriented API is provided. Libzdb supports MySQL, PostgreSQL, SQLite, and Oracle.
LMDB is an ultra-fast, ultra-compact key-value data store developed by Symas for the OpenLDAP Project. It uses memory-mapped files, so it has the read performance of a pure in-memory database while still offering the persistence of standard disk-based databases, and is only limited to the size of the virtual address space (it is not limited to the size of physical RAM).