Elefant is a full-featured, but refreshingly simple CMS and PHP Web framework. It features an intuitive, streamlined admin interface, a tightly integrated WYSIWYG editor, dynamically embeddable content objects for building dynamic Web sites without touching code, and an extremely fast, secure, and flexible framework for add-ons and themes. The core CMS includes page editing, a blogging engine, site navigation, file and user management, automatic version control, a tool for translators and multilingual site management, and an in-browser theme/layout editor. It is also extensively documented and has a small but friendly and active developer community.
Haystack is a powerful tool designed to enable each and every individual manage all of her information in the way that makes the most sense. By removing the arbitrary barriers created by applications that only handle certain information "types", and recording only a fixed set of relationships defined by the developer, users can define whichever arrangements of, connections between, and views of information they find most effective. Such personalization of information management will dramatically improve your ability to find what you need when you need it.
Poedit is a gettext translation (.po file) editor for Unix, Windows, and OS X. It aims to provide translators with a simple, easy to use user interface with all the essential tools such as spellchecker or translation memory. It can also be used to manage translations for small projects.
Gfarm is a distributed filesystem, generally used for large scale cluster computing. It's implemented in userland, and can be mounted by FUSE. It utilizes locality of a file to access a data node, and supports Globus GSI for Wide Area Network. Users can explicitly control file replica location on Gfarm. Gfarm can be used as an alternative storage system to HDFS for Hadoop, Samba, MPI-IO, and GridFTP. Monitoring via ZABBIX and Ganglia is also supported.
NLopt is a library for nonlinear optimization that allows one to select from a wide variety of optimization algorithms by changing a single parameter. Its features include both local and global optimization, unconstrained, bound-constrained, or nonlinear-inequality constrained problems, and optimization using function values only or using derivatives if they are available. It was initially begun as a wrapper around several existing optimization packages, but it now also includes original implementations of several algorithms for which no free code was available. It provides interfaces callable from C/C++, Fortran, Matlab, GNU Octave, Python, and GNU Guile.
The libQtCassandra library is an advanced C++ library used to access Cassandra servers. Unlike the basic Cassadra server interface, this C++ library provides separate objects that handle each level of the server data, i.e. the cluster, contexts, table, rows, and cells. It uses Qt and the Qt style for all the classes, which makes it very easy to use if you already know Qt.