[jcynix]

> There is some question whether CTAN (for TeX) or CPAN was the first big library.

There isn't "some question", there is a definite answer, namely in "Programming Perl" and I quote the 4th edition, page 629:

History

Toward the end of 1993, Tim Bunce, Jarkko Hietaniemi, and Andreas König set up the perl-packrats mailing list to discuss the idea of an archive for all the Perl 4 stuff floating around the Internet. Perl 5 development had started that year, and one of its main features would be an extensible module system that would allow people to extend the language without changing perl. Jared Rhine suggested he idea of a central repository, but nothing much happened. His idea had come from CTAN (http://www.ctan.org), the Comprehensive TeX Archive Network.

Edit: fix markup