bmk-mgr implements the tree-like bookmark manager kind of thing found in other browsers. Although i use it with emacs-w3m, it can interoperate with any browser. (View source)
emacs-w3m is a tabbed browser: this package lets you store and recover the set of open tabs at any moment. (View source)
This is a very quick hack that uses GNU Mailutil's frm program to display, inside an emacs buffer, the contents of your mailbox. It can also serve as an example of how to write a simple emacs mode. (View source)
Here you'll find the set of skeletons i use for autogenerating source code file templates. (View source)