If you're starting a new project, should you choose an Open Source solution, using software that's free at the point of distribution and for your use, or should you spend money buying a commercial piece of software?
|First reaction - use open source|
"why pay when you can get something for free"
| ||Second reaction - use commercial|
"I need help and support and I can get that if I pay money for software"
It's not as straightforward as either of those answers though. You should look at the total cost of ownership.
With Open Source software, you'll tend to have far more options and alternatives available to you within the products, with hosts of addons available, most of which will be excellent. So although you'll save on purchase price, you may end up spending more in terms of your own / your programmer's time on your first project than you would if you had chosen to use a commercial product. But once you know the Open Source software well, you'll be able to make good use of those alternatives and flexibility, and on the second and subsequent projects the Open Source route should be much quicker.
Do you want training? There *are* exceptions, but training on commercial products tends to be more expensive, and is sometimes MUCH more expensive. If you've bought a commercial piece of software, you'll tend to gravitate to the author / supplier company for your training too; they know this, and sometimes it's the training rather than the software sales price that makes them their money. Third Party trainers (I used to work for one) have software licensing issues for their training machines, and may be "strongly encouraged" to run official courses for which a per-delegate royalty is payable to the author company.
There's sometimes an assumption made that you can't get support on Open Source software. That's wrong, there are companies who will sell you support. If you're a bit of a geek (or even minigeek) you'll find a lot of support in newsgroups, postings, forums, etc.; other users of open source (and authors) are typically very proud of what they've done. Common questions - go through existing resources / searches. Less common ones - the forums and people behind the software may love the challenge.
The question has been asked of me "but what if Joe Bloggs, author of K++, gives up on it and I've used K++ in a business critical application?"
It's a good question, but let me ask another question: what if [big corporation], author of J++, gives up on it and I've used K++ in a business critical application?"
The answer - when you think about them - are a bit of a surprise. If the author of the Open Source product gives up, you've got the source code of it. So in the worst case you can employ someone to fix issues. If the author of a commercial pece of code gives up on it when there are business critical users out there, it's writing itself something of a blank cheque to charge them for ongoing support if it chooses to do so ...
My diagram stacks up the various costs for a newcomer's project, and for an experienced user's project, using commercial and open source software. Of course, the sizes of the boxes here are purely illustrative so where my diagram shows one approach winning over the other, you may find that it's the other way round for your particular needs. (written 2011-03-26)
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articlesQ050 - Object Orientation and General technical topics - General Technical Subjects 
Big number - (2005-10-12) 
Should I maintain the programming code on my own website? - (2009-03-23) 
Looking for a practical standards course - (2009-08-05) 
Forums for your Melksham and open source discussions - (2010-01-09) 
The Merchants And - (2010-06-09) 
Public and private courses - subjects available for 2011 - (2010-12-29)G914 - Well House Consultants - Other Software 
It's just not cricket - (2004-10-06) 
Learning to Twitter / what is Twitter? - (2009-03-28) 
RT @brento - a valuable source for the twitter newbie - (2009-05-20) 
Windows 7 and Open Source Programming - (2009-10-22) 
Go Programming Language and Courses? - (2010-01-26) 
Switching from Adobe Photoshop to Gimp - testing it on animals - (2010-08-06) 
QR codes - graphics images that provide quick phone links - (2012-01-18) 
Seeing how Melksham has changed over the years, via an iPad - (2012-01-30) 
iPad and iPhone programming - our seminar weekend with Xcode - (2012-03-11) 
An email marathon - (2012-10-15) 
Email from Christopher Columbus to announce finding America? - (2013-01-29) 
Using Pygments to colour our training examples - (2013-03-10) 
Libre Office - unable to get past REOPEN WINDOWS? question - (2014-09-22) 
FileMaker Day to Unix Time conversion - (2015-02-15)
Some other Articles
Vandalism and riot from the minority - the effectImages of a Spring WalkSolution looking for problemMelksham Campus - any last minute inputs from Melksham businesses?Should I use Open Source or Commercial software?Well House Manor - a home from home for the business and leisure guest in MelkshamComputer Graphics in PHP - World (incoming data) to Pixel (screen) conversionCatchable fatal error in PHP ... How to catch, and alternative solutions such as JSONSeeing Electricity Pylons near MelkshamLinks for social media, microblogs and business networking