At times, I will run hints here which are pointers to third-party apps that seem to do interesting things. The decision as to whether to run such a hint is purely subjective; if it seems like the program does something interesting, then I'll usually run it. If it's open source, the odds are even higher, as perhaps someone will learn something by looking at the source. And almost always, these apps will be from small one-person shops, who typically have trouble getting the word out about their programs.
On the other hand, I don't want macosxhints to turn into a software update and release announcement site, so I'd rather not have such hints be the majority of our content. So it's a fine balancing point between providing useful information to the community and straying too far from the site's real mission of providing OS X hints.
Over the last week or so, I've received quite a few such "this app does XYZ" type of hints. Instead of running each as a separate "hint," I thought I'd just post them here as a collection of potentially interesting free apps. Note that I have not necessarily tested any of these; I just thought some portion of the community might find them of interest. All of them are free, and some include source.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20061220065842930