SETL

ISETLW
Interactive SET Language for Windows 9x/Me/NT/2000/XP: downloads, documentation, bugs, sample problems.
http://isetlw.muc.edu/isetlw/

SETL2
SET Language 2, close relative of SETL, has some clumsy support for closures, an experimental (broken) object system, and redefines integer division to mean something different than in SETL: 3/2 yields 1.5 in SETL, but only 1 in SETL2.
ftp://cs.nyu.edu/pub/languages/setl2/

SETL Documentation
SET Language: mathematical programming language closely resembling the language of sets and functions used by Mathematicians. Lets users define sets, then define functions and binary operations on the sets: reference documentation for the library of built-in operations.
http://cs1.cs.nyu.edu/bacon/setl-doc.html

SETL for Internet Data Processing
A dissertation by David Bacon.
http://cs1.cs.nyu.edu/~bacon/phd-thesis/diss/

SETLS
FTP site with version 2.2, for PCs using DOS; downloads of self-extracting .exe.
ftp://cs.nyu.edu/pub/languages/setls/