The list library defined in SRFI-1 contains a lot of useful list processing procedures for construction, examining, destructuring and manipulating lists and pairs.

This package provides the SRFI-13 string library for Chicken scheme.

Character sets can be created, extended, tested for the membership of a characters and be compared to other character sets

The threads implemented in CHICKEN are so called "green" threads, based on first-class continuations. Native threads that map directly to the threads provided by the operating system are not supported. The advantage of this is that threads are very lightweight and somewhat larger degree of determinism. The disadvantage is that execution of Scheme code on multiple processor cores is not available.