what is Perl?

Practical Extraction and Report Language (Perl) is a general-purpose programming language originally developed for text manipulation and now used for a wide range of tasks including system administration, web development, network programming, GUI development, and more.

advantages of Perl

Perl is an open source program which is easy to learn if you have experience with a few different programs. The language is intended to be practical (easy to use, efficient, complete) rather than beautiful (tiny, elegant, minimal).
Its major features are that it's easy to use, supports both procedural and object-oriented (OO) programming, has powerful built-in support for text processing, and has a large collection of third-party modules.
Another of the advantages in using Perl is due to the fact there are always several ways in performing one operation.

relevant books about Perl

• Learning Perl on Win32 Systems
• The Perl 5 Programmer's Reference
• Perl/TK Pocket Reference
• Perl: Annotated Archives
• Programming Web Graphics with Perl & GNU Software (O'Reilly Nutshell)
• Writing Perl Modules for CPAN
• Perl for Web Site Management
• Beginning Perl for Bioinformatics
• Writing Perl Modules for CPANPerl for the Web
• Perl CD Bookshelf 2.0 CD-ROM
• Perl: The Complete Reference
• Programming the Perl DBI
• Writing Apache Modules with Perl and C
• Perl: The Complete Reference
• mod_perl Pocket Reference (Pocket Reference (O'Reilly))
• Core Perl

• Perl
• Wikipedia definition