PHP On Pie is a PHP framework that combines the best ideas from PHP projects like Drupal, CodeIgniter, Kohana, and ZendFramework. It has very few core concepts: classes, models, events, slots, and tools. It lets you repackage completed apps into plugins that you or others can use later. Its smart database classes allow you to implement vertical and horizontal partitioning (sharding) easily to handle millions of users.
Metakit is a small, portable database library using a hybrid relational / hierarchical data model with a column-wise internal storage format. For C++, include a single header file and 125 kb DLL or statically link directly. Ideal for desktops, embedded systems, smartphones, and PDAs. Bindings for Python and Tcl. A very mature, stable code base.
txtorcon is a Twisted-based asynchronous Tor control protocol implementation. Twisted is an event-driven networking engine written in Python, and Tor is an onion-routing network designed to improve people’s privacy and security on the Internet. It includes unit-tests with 96%+ coverage, multiple examples, and documentation. There are abstractions to track Tor configuration and state (circuits, streams), launch private instances, support Hidden Service, and more.
Diakonos is a customizable, usable console-based text editor. It features arbitrary language scripting, an interactive help system, bookmarking, regular expression searching, parsed ("smart") indentation, macro recording and playback, a multi-element clipboard, multi-level undo, a customizable status line, completely customizable keyboard mapping, and customizable syntax highlighting.
C++ Resources Compiler is a tool that will generate a C++ source file (along with the corresponding header file) that embeds any given data file and provides a Resource class which gives access to this data. The Resource class can be created in two flavors: one using STL streams, the other using WxWidgets streams. Its function is similar to that of the "qtrc" tool from the Qt toolkit.
muhttpd (mu HTTP deamon) is a simple but complete Web server written in portable ANSI C. It supports static pages, CGI scripts, and MIME type based handlers. It drops privileges before accepting any connections, and can log received requests. It has been tested on OpenBSD, GNU/Linux, NetBSD, FreeBSD, Mac OS X, and Cygwin. It runs successfully on 32-bits, 64-bit, little endian, and big endian systems.