I didn't do a Linux audit because all of my Linux software is Open Source with one exception: Lotus Domino.
I broke down the software into several categories: FOSS (Free & Open Source Software), Gratis (Freeware), and COTS (Commercial Off-the-Shelf). Shareware is considered COTS, since I pay for that.
Here's a summary of the results:
- FOSS: 20 programs
- Gratis: 32 programs
- COTS: 11 programs
The interesting part is the type of programs that fall into each category. Gratis programs are typically such things as file readers and browser plug-ins, and small utilities that are nice to have, but not essential. COTS software encompasses those things that I consider to be best in their class (such as FTP Serv-U and Lotus Notes), and also things that I just have to have to do my job (programming languages such as Visual FoxPro).
It was interesting, though, that many of the workhorse programs (OpenOffice.org, Firefox, the GIMP, Open Workbench) are FOSS. Even in the case of the commercial software that I use, Lotus Notes is the only one I've bothered to upgrade recently, and I use that as a platform for writing FOSS. I've had no justification for upgrading anything else. Once you have a text editor, even one as nice as Textpad, do you really need to upgrade it? In my case, no. And though I have Microsoft Office 97, I haven't actually used it the last several weeks. It's there "just in case."
So I'm finding that my commercial software inventory is losing relevance and simply isn't as competitive as the FOSS alternatives.
If you'd like to see some thoughts about why I use this or that piece of software, you can read the current list. This PDF, incidentally, was generated with OpenOffice.org.