distinct projects began in
1981 and 1982 to use variants of Scheme for courses at MIT, Yale, and
Indiana University&nbsp;[<a href="r5rs-Z-H-14.html#%_sec_7.3">21</a>,&nbsp;<a href="r5rs-Z-H-14.html#%_sec_7.3">17</a>,&nbsp;<a href="r5rs-Z-H-14.html#%_sec_7.3">10</a>].  An introductory
computer science textbook using Scheme was published in
1984&nbsp;[<a href="r5rs-Z-H-14.html#%_sec_7.3">1</a>].<p>

As Scheme became more widespread,
local dialects began to diverge until students and researchers
occasionally f