"[U.S.] job ads requesting open source skills,..[have] seen the following growth since Jan [2007]...

• AJAX: 100%
• PHP: Practically "doubled since January, [2007]"...
• Python: 72%
• MySQL: 50%
• Ruby on Rails: 121%.
• Perl: 22%. Perl,.. 'is not so sexy, but it makes the Web go 'round.'"

More: http://itmanagement.earthweb.com/career/article.php/3697896