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.
MundoCore is a lightweight and easy-to-use communication middleware to integrate heterogeneous software systems, consisting of services written in different programming languages and running on different operating systems. It also offers specific support for mobile and ubiquitous computing environments.
db4o is an object database for Java and all .NET environments. Its features include ACID transactions, automatic class schema recognition, query-by-example, a S.O.D.A. object querying API, native queries, LINQ support on .NET, callback methods, memory files, cascade-on-delete, multi-threaded access, and Java Webstart and servlet support.
edtFTPnet/Compact is an FTP library for the .NET Compact Framework. It will run on all mobile devices that support the CF, including PocketPC and Windows CE. It includes support for active and passive transfer modes, SOCKS and HTTP proxies, extensive event monitoring, directory transfers, and transfer resumption. HTTP downloads are also supported.
Piccolo2D is a toolkit that supports the development of 2D structured graphics programs, in general, and Zoomable User Interfaces (ZUIs), in particular. A ZUI is a new kind of interface that presents a huge canvas of information on a traditional computer display by letting the user smoothly zoom in to get more detailed information and zoom out for an overview. It uses a "scene-graph" model that is common to 3D environments. This means that Piccolo maintains a hierarchical structure of objects and cameras.
SuperWaba is a VM for PDAs. Because of the way it was written, you can use Java to develop programs for it. It supports exceptions, threads, many user interface controls, double and long 64-bit types, grayscale, color, 3D controls, and JNI and Java libraries, among other features. The project has been superseded and replaced with TotalCross.
Pixane is an image processing library for Tcl that allows the scripting of all kind of image transformations. It supports reading from and writing to a large set of file formats (JPEG, PNG, GIF, BMP, WBMP, etc) and provides anti-aliased text rendering and a set of built-in fonts. It doesn't requires Tk, so it can be used to easily generate images dynamically from CGI. Binaries are provided for many platforms as dynamic libraries with no external dependencies for easy deployment. It is also a core component of the eTcl distribution.