muCommander is a cross-platform file manager with a dual-pane interface that features support for FTP, SFTP, SMB, NFS, HTTP, Amazon S3, Hadoop HDFS, Bonjour/Zeroconf, email attachments, archives in many formats (including Zip, RAR, 7z, GZip, Tar, Bzip2, ISO, NRG, AR, Deb, and LST), bookmarks, credential management, themes, multiple windows, full keyboard control, and many configuration options. It is available in 23 languages.
Ingres is a feature rich and robust database (RDBMS) that's free to use, modify, and redistribute. Support is available for a reasonable price if you need it. Ingres supports many programming languages, including Python, Ruby, Java, Perl, C/C++, and more. Ingres has a bit of a learning curve, but once mastered is extremely powerful and highly tunable. It is also very stable and reliable. Ingres is one of a fairly small number of databases providing excellent geospatial features including data types and functions compliant with the Open Geospatial Consortium (OGC) Simple Feature Specification (SFS) for SQL.
OpenAMQ is a fast, stable, free implementation of the AMQP (www.amqp.org) messaging protocol. It gives applications high-performance messaging (delivery of opaque data) across loosely connected networks. It is capable of handling up to 600k messages per second depending on the hardware, with a latency around 300 microseconds. It is multithreaded and supports C/C++ and Java on Linux, AIX, Solaris, OS/X, Windows, and OpenVMS.
PD4ML is a powerful PDF generating library that uses HTML and CSS for page layout and content definition. It allows developers to easily add PDF generation functionality to software written for the Java and .NET platforms. PD4ML is easy to deploy and does not rely on any native components. It is based on a proprietary HTML rendering engine, optimized for PDF layout generation. The rendering engine implements most standard features of HTML4/CSS2 and a number of custom PDF-generation-specific functions for pagination control, header/footer generation, watermarking, TOC generation, margin control, etc. PD4ML allows you to easily embed word processor documents, spreadsheets, and rich media content as attachments to the resulting PDF documents.