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 written in ANSI-C. It includes B+Trees with variable length keys and records. It supports in-memory databases and endian-independent files, database cursors, multiple databases in one file, "record number" databases, and duplicate keys. hamsterdb is very fast and highly configurable. It compiles and runs on Unix platforms, Linux, Microsoft Windows, and Windows CE.
CodeBase is a high-speed xBASE compatible database engine for C/C++, Visual Basic, Delphi & Java programmers. You can use CodeBase to write high performance database applications that are multi-user compatible with FoxPro, dBASE and Clipper, create anything from a Java applet to a full-blown Windows database application to a simple DOS utility, write scalable applications that can be deployed as single-user, multi-user or client/server, all without changing any of your source code, and port your applications to Windows, DOS, UNIX, OS/2, and Macintosh. There's a free 30-Day Test Drive option available. CodeBase is available for every major operating system including Windows XP, 2000, 9x, NT, CE, DOS, OS/2, Macintosh, and a variety of Linux and UNIX platforms including Solaris, SunOS, HP/UX, AIX, SCO, and others.
xdata implements an interface to arbitrary key-value pairs which are accessible to simple shell and Perl programs. Applications for this include to-do lists, contact databases, browser bookmarks, and anything else which requires small pieces of data to be referenced by keys. xdata stores timestamps for the data it manages, and comes with a program to synchronise databases among cooperating hosts. This allows you to propagate information among hosts in a transparent fashion (creations, updates, and deletes are correctly handled). xdata consists of a set of shell-level utilities and a Perl module.
FlagShip is a database development and porting system for moving xBase-based languages to Unix. It is a highly-optimized 4GL language, syntactically compatible to other xBase dialects like dBase, Clipper, Fox, etc. It is object oriented, but you don't need any OOP knowledge to use it. It supports the same code for DOS and Unix. It allows you to add C sources externally or inline in the program source, but does not require any C knowledge.
The c-tree Plus embedded database engine offers developers several APIs that provide low-level routines, ISAM-level control, and higher-level interfaces. c-tree Plus is distributed in complete C source, has been ported to 100+ environments and includes a robust database Server SDK. It can be used to develop single user and peer-to-peer applications, or the client-side for applications using FairCom's database server, the c-tree Server.