You have a computer system that's working for your business. But there's always something extra that you wish it could do. For the last 20 years I've been adding those little extras to systems.
When I started I had to learn assembly language to change the look of various printouts. The song "99 Bottles of Beer" in assembly language. As software got more features they came with their own languages to customize them. I learned these well enough to keep my job.
Now we have HTML, XML, CSS, VBA, bash, .NET, C#, SQL, Perl, Python, Java, and Javascript, to name a few, ways to customize YOUR system. You didn't buy the machine to pay attention to backslashes and semi-colons. You tell me what you want to do and I'll tell you how I'll approach it.
Linux
When I was at the Houston Chronicle IBM had started installing a Linux-only CPU in their enterprise server boxes. I was part of the team that installed and test SUSE linux on the box.
After I left the Chronicle I knew Linux was the next growth market in IT. The open systems market is filled with very smart and helpful people. I spent part of my severance on a Red Hat Linux system administration course . The tuition included a copy of Red Hat Enterprise Server that I put on my laptop.
Now I have a new laptop and a new distribution of Linux, Ubuntu . It is so widespread it has been mentioned on the Big Bang Theory.
Microsoft
I learned to work with Windows Server 2003 at Freedom Equity Group, a small insurance firm with 4 users. I used this experience to get a job as a system manager at an oil and gas risk consultancy with over 20 engineers that traveled the world checking the safety of oil rigs and natural gas plants as they were being built.
When they had outgrown the server software and wanted the features of Exchange 2008 I upgraded them to WS 2008. This laid the groundwork for converting
from Exchange 2003 to 2007.
When I got there they were using Word 2003. The officers of the company used Macs. When the Macs got an upgrade to their Office suites the company had to upgrade to Word 2007. I did the ordering and installations for the staff.
My Excel and HTML work helped a microbiology professor publish chromosone maps to a frog
Mainframe
When I started in IT I had to customize software packages with assembly language exits. Later I learned various proprietary scripting languages as the packages became more user-friendly.
As the network became the computer I learned how to configure RAID boxes for mainframe and Windows storage. My box and its software could print a one-page email on Laserjets while putting out a million-line monthly circulation billing run. I configured redundant Ethernet cards and Gigabit cards.
When the schools started phasing out COBOL I was part of the team that installed and supported an secure Open systems environment and compilers. This environment gave us the basis to run a web server and e-mail system off the mainframe.