For example, OpenOffice. Why give Microsoft your hard-earned cash when you can have OpenOffice for free? And why chuck even more money at Microsoft for Windows XP when you can get Linux for nothing?
OK, you'll probably need to pay a few pounds to have someone compile and ship it to you (complete with manuals and a nice set-up program), so get RedHat's latest personal edition (7.3). At €83.31 (or about £53), it's basically free as far as I'm concerned.
The personal edition of Linux doesn't come complete with developer tools, but there's plenty of free everything for Linux, and they're just a download away.
Talking of developer tools, I reckon Microsoft's "new" programming language C# is OK. But I don't really want to give Microsoft any money for an integrated development environment (IDE), especially as the company put the language spec into the public domain.
Here's the good news: I don't have to, as there's a free C# IDE out there called SharpDevelop - and it is truly great.
Of course, if you like the C# and Linux combination - well, there'll soon be a .net development framework for you to work with as well (follow the Mono .NET Development Framework link below).
Lastly, as I'm connected to the Internet 24/7, I need a firewall (ZoneAlarm's free version) and, just in case some legacy virus gets mailed to me - I want to run some antivirus software (AVG's free version).
There's plenty of other great and reliable software out there, of course - Web and content servers (not just Apache), CRM systems, newsgroup-readers/mailers and Web-browsers.
The bottom line is, why pay good money for what you can get free? Especially if it helps untie your hands as well as saving you money.
If you want to follow Peet Morris on the free (or cheap) software trail, here are some useful links.
SharpDevelop (C# IDE)
Linux operating system
ZoneAlarm Pro firewall
Mono .NET Development Framework
Mozilla open source Web browser
Opera Web browser
Peet Morris has been a software developer since the 1970s. He is a D.Phil (PhD) student at Oxford University, where he's researching Software Engineering, Computational Linguistics and Computer Science.