The Xoltar Toolkit contains utility modules for Python, including functional
programming support, lazy expressions and data structures, and thread pools.

It includes support for closures, curried functions, lazy expressions,
lazy tuples (functional programming languages call these lazy lists, but
since lists are mutable in Python, tuples are closer in meaning), and lazy
equivalents for map, filter, reduce, and zip.  It also includes some
higher-order functions for composing functions.

WWW: http://sourceforge.net/projects/xoltar-toolkit/
See also: http://www-106.ibm.com/developerworks/library/l-prog.html