Mailvisa is a spam filter along the lines of Paul Graham's "A Plan for Spam". It classifies messages by comparing the words in them to known spam words. CPU usage, filtering speed, and filtering accuracy are comparable to other Bayesian filters. Mailvisa was originally intended as a platform for experimentation with different filtering parameters, but it has evolved into a useful spam classifier. In the author's own use, the amount of spam caught has surpassed 95% with no false positives so far.
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.
The Voodoo compiler is an implementation of the Voodoo programming language. The Voodoo programming language is a low-level programming language, abstracting over the platform's instruction set and calling conventions, but otherwise leaving the programmer free to do anything at all. The Voodoo compiler supports multiple target platforms and provides a stand-alone compiler, as well as a Ruby module for programmatic code generation.
cconstants is a library and a set of commandline utilities which allow the values of constants defined in C header files to be queried outside the C preprocessor. This allows the values of these constants to be queried from programming languages other than C, on systems without the C preprocessor installed, and on systems on which the header files defining these constants are not available.
wxWindows Theming and Qt Licensing
Actually, wxWindows does support theming. On *nix systems, it can use GTK+ as a backend, and GTK+ is fully themable. The wxUniversal port provides its own widgets, which are also themable. wxMotif is the only version I know isn't themable at all, even the MS Windows port is themable so some extent (namely through various skinning programs for Windows).
Now for something completely different: Qt under GPL. I think Trolltech was justified in their concerns about releasing under GPL. IANAL, but I think the GPL has two properties that enable one to legally write non-GPLed software with the Free version of Qt.
Fisrt, the GPL explicitly forbids putting further restrictions on distribution and use, including Qt's demand that the Free version only be used for developing Free software. As it stands, the Qt code becomes part of the final product, thus requiring that product to be GPLed. However, Qt may be modified so that this is no longer the case (i.e. thelibrary and the application become completely separated).
Secondly, the GPL requires a larger work to be released under GPL if and only if that larger work is distributed at all. This means that one could perfectly legally develop a larger work for use in-house without releasing a bit of source code.
This is not to say that I advocate punishing Trolltech for doing something that has greatly benefitted the OSS community and themselves alike. I am just sharing my thoughts, and hoping someone can enlighten me.