Added "Practical mod_perl"

free-programming-books.md

@@ -1076,6 +1076,7 @@ See also [TeX](#tex)
 * [Essential Perl](http://cslibrary.stanford.edu/108/EssentialPerl.pdf) (PDF)
 * [Extreme Perl](http://www.extremeperl.org/bk/home)
 * [Higher-Order Perl](http://hop.perl.plover.com/book/)
+* [Practical mod_perl](http://modperlbook.org/) - Stas Bekman, Eric Cholet
 * [The Mason Book](http://www.masonbook.com/book/)
 * [Mastering Perl](http://chimera.labs.oreilly.com/books/1234000001527) - Bryan D Foy
 * [Modern Perl 5](http://www.onyxneon.com/books/modern_perl/index.html)