Scheme Code Extensions: Collections of miscellaneous Scheme code.

lang/scheme/code/ext/

   arrays/    Multidimensional arrays in Scheme
   avl/       AVL: AVL trees and tries.
   function/  Extensions related to functions
   hash/      General Table: Hash table implementation for 
              Scheme
   lattices/  Lattices: Jim Miller's Conform package.
   lists/     Code for manipulating lists of various kinds.
   resource/  Resources: Implementation of resources (weak 
              pools) for Scheme.
   sets/      Code for implementing sets of integers.
   strings/   Scheme code for manipulating strings and 
              characters.
   structs/   Implementation of Structures for Scheme.
   threads/   PCALL: Scheme code to emulate FUTURE and PCALL.
   trees/     Code for various types of tree structures.
   types/     Code related to Types.