The Math Archives provides Internet access to a wide variety of mathematical resources. The primary emphasis is on materials which are used in the teaching of mathematics. Eventually, when ISETLW has developed a little further, it will be submitted to the Math Archives. Meanwhile, you can still get ISETL for DOS there.
ISETL for DOS is located under Discrete Math software under the MSDOS platform in the archives. Also, ISETL for Mac is located under Discrete Math software under the Mac platform in the archives.