An Experiment ....
Perl is a computer language.
You write a series of instructions and the computer then performs them. Unless you state otherwise, statements are performed in order. You can, though, have conditional code, loops and calls to blocks of code elsewhere just as in other languages.
Perl has much more in its language than most programming languages. It's both eclectic (many ways of doing things from many different sources) and wide ranging in itself. And there are a lot of other resources available to let it go even further.
What does Perl cost?
Perl itself costs nothing. It's distributed under an artistic license
which gives you the right to copy and use it for free under most conditions, and even to modify it in many circumstances!
What is Perl used for?
Deep breath. Anything. Everything. Seriously, though ...
[82][ac][c2] Data manipulation
[82][ac][c2] Installation scripts
[82][ac][c2] System management
[82][ac][c2] Daemons
[82][ac][c2] Network services
[82][ac][c2] World Wide Web interaction
[82][ac][c2] Database interfacing
What computer do I need to run Perl?
Perl is a very efficient language. You don't need anything too powerful and it runs cross-platform. Common and supported ports include:
[82][ac][c2] Windows 95, 98, 2000, ME, NT, XP, Vista and 7
[82][ac][c2] Solaris 2.x, Solaris 7, Solaris 8, Solaris 9, Solaris 10
[82][ac][c2] Mac OSX
[82][ac][c2] Linux (All flavours including Mandrake, SuSE, Redhat, Knoppix, Ubuntu, Centros and Caldera)
[82][ac][c2] AIX3, 4
[82][ac][c2] SunOS 4.1.x
[82][ac][c2] Free/Open/Net BSD
[82][ac][c2] Irix 4, 5, 6
[82][ac][c2] Ultrix 4
[82][ac][c2] HPUX 9, 10
[82][ac][c2] Digital UNIX / DEC OSF/1 1, 2, 3, 4
[82][ac][c2] Mac Classic
[82][ac][c2] Ms-Dos
[82][ac][c2] Windows 3.1
[82][ac][c2] Amiga
[82][ac][c2] AS400
[82][ac][c2] VMS
[82][ac][c2] Tandem Guardian
[82][ac][c2] MVS
[82][ac][c2] Lynxos
[82][ac][c2] Novell Netware
[82][ac][c2] NextStep
[82][ac][c2] OS2
[82][ac][c2] Acorn RiscOS
[82][ac][c2] Siemens Sinix
[82][ac][c2] SCO Unixware
And it runs virtually the same way on all platforms!
Why did I start this article with the words "an experiment"? Because I'm experimenting with updating our course content via HTML.

The text above is from an early chapter of our
Perl Programming and
Learning to Program in Perl courses. Currently, we produce a manual of around 300 printed pages (which gets excellent reviews) to cover the course - using Adobe FrameMaker for maintain the documents. However, the system is getting to be an old one and whilst we are not looking to replace something that's doing very well for us just for the sake of it, we are asking ourselves what other techniques we could use to make out documentation even better, even more up to date, and quicker and easier for you (the customer) to reference and us (the material producers) to handle.
We do hear the comment "how great to have a really useful manual" and "I'm so glad it wasn't another Power Point presentation" - and you can rest assured that we won't be looking to reduce the utility of what we provide. And if we
were to switch to Powerpoint, it would certainly not be in such a way that we would be producing a slick presentation to the detriment of good, complete content that's useful to our delegates during the lectures, the practical sessions that follow them, and back in their own offices as they write their own programs too.
Illustration - delegates on a recent private Perl course which I ran for a client at his own offices. We run public courses which are open for anyone to sign up to at our Melksham, Wiltshire training centre, and private courses at any location worldwide (subject to visa regulations and the safety of the instructor - we turned down Bagdad just before the outbreak of the second gulf war ...)
(written 2010-06-15, updated 2010-06-18)
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
P201 - Perl - Introduction [25] Release numbers - (2004-08-23)
[317] Programming languages - a comparison - (2005-05-20)
[382] Central London Courses - Perl, PHP, Python, Tcl, MySQL - (2005-07-18)
[577] Learning to program in Perl or PHP - (2006-01-26)
[594] Twice is a co-incidence and three times is a pattern - (2006-02-07)
[604] Perl - multiprocess applications - (2006-02-13)
[629] Choosing the right language - (2006-03-01)
[691] Testing you Perl / PHP / MySQL / Tcl knowledge - (2006-04-19)
[743] How to debug a Perl program - (2006-06-04)
[846] Is Perl being replaced by PHP and Python? - (2006-08-27)
[924] The LAMP Cookbook - Linux, Apache, MySQL, PHP / Perl - (2006-11-13)
[1717] Q - Should I use Perl or Python? - (2008-07-23)
[1753] Perl v PHP, choosing the right language - (2008-08-14)
[1852] Perl and Blackberries - (2008-10-23)
[2070] Converting to Perl - the sort of programs you will write - (2009-03-08)
[2832] Are you learning Perl? Some more examples for you! - (2010-06-27)
G504 - Well House Consultants - Writing Notes [4] Seeing the wood for the trees. - (2004-08-06)
[7] Writing on a Sunday - (2004-08-08)
[9] Study room - the Oxford train - (2004-08-10)
[394] A year on - should we offer certified PHP courses - (2005-07-28)
[398] Training course material - why we write our own - (2005-07-30)
[407] Theft of training material - (2005-08-09)
[797] Writing up new C / C++ notes. - (2006-07-09)
[979] Empty seats, Nodding Donkeys and buses - (2006-12-11)
[982] Notes from the white board - (2006-12-14)
[1950] Copyright of Training Notes and Web Site - (2008-12-18)
[2010] How long should a training module be? - (2009-01-27)
[2192] Copy writing - allowing for the cut - (2009-05-21)
[2414] Hello World - a good traditional start to a Java course - (2009-09-22)
[2481] Sample code with errors in it on our web site - (2009-10-29)
[2828] Sharing our programs - easy. Sharing our data - harder. - (2010-06-26)
[3152] Jargon busting - (2011-01-30)
[4009] Clear, concise examples - Ruby classes and objects. - (2013-02-17)
[4031] Showing what programming errors look like - web site pitfall - (2013-03-06)
Some other Articles
Intelligent Matching in Perlswitch and case, or given and when in PerlPython - splitting and joining stringsIterating over a Perl list and changing all itemsWhat is Perl?Igloos melt in the summer, but houses do notA course review - for the tutor to completeFrankfurt in 90 minutesFrom home to Nurnberg - journey picturesCanal through Melksham - the options and issues