Boost library Cookbook. A site of code recipes for Boost C++ library.

The official set of online Rails manuals, including a Rails cookbook and a good guide on Rail’s URL routing/rewriting. The docs for a user login plugin and an overview of plugins in general.

Programming Language Examples Alike Cookbook (PLEAC), a project to solve common programming problems in a multitude of languages.

The Linux Cookbook: Tips and Techniques for Everyday Use.

Snacksby, a very web2.0 recipe site. Give it a list of crap in your fridge and it returns a list of tasty dishes that fit your available ingredients. Not what I was planning to work on with CookBookr.com, but an interesting approach nonetheless.

A geek-friendly recipe: Liquid Nitrogen Ice Cream.

101 Cookbooks presents the best pizza dough ever. We tried this recipe yesterday (and loved it), and the site looks good too.

The Ground meat cookbook, 204 disturbing recipes. Note that these recipes would probably work for soy-meal as well (which is less dangerous in every way).  This book is a great example of recipe books from the era, with some nifty retro typography and layout.