A series is a data structure much like a sequence, with similar kinds of operations. The difference is that in many situations, operations on series may be composed functionally and yet execute iteratively, without the need to construct intermediate series values explicitly. In this manner, series provide both the clarity of a functional programming style and the efficiency of an iterative programming style. Series is the culmination of many years of design and use of this approach, during which some 100,000 lines of application code have been written (by about half a dozen people over the course of seven years) using the series facility in nearly all iteration situations. This includes one large system (KBEmacs) of over 40,000 lines of code. In a nutshell: Think "Efficient MAPCAR". SERIES translates functional-style expressions into efficient loops.
Lisppaste is a fully-featured pastebot that provides a Web interface to submit pastes, and announces the URL the paste is stored at to a channel of your choice. It features multiple channel support, paste annotation support, persistent pastes, a Web interface to the list of pastes in the system, RSS support in short and full varieties, XML-RPC support, and direct linking to meme IRC logs.
NTW Lisp is a server written in Common Lisp for applications that use the NTW protocol to communicate with a GUI client. This asynchronous protocol makes it possible to serve remote applications that are indistinguishable from native ones. It's also useful for quickly writing GUI apps from Common Lisp that can be run locally.