Open Source Software
Open Source Software is software for which the underlying programming code is available to the users so that they may read it, make changes to it, and build new versions of the software incorporating their changes. Some examples you may have heard of are Firefox and Linux.
The PC recently did an exhausting (rather than exhaustive) Open Source project for IST’s Technical Architecture Committee. The project involved creating an open-source web mapping solution using Linux, Apache, MySQL, PHP, and MapServer. You can get a full gander at the report here.
Open source solutions will probably be effecting your world in the near future. For web developers, it already has. With IE at or slightly below 90% and falling since Firefox 1.0’s release, standards-based web development is no longer optional.
If you want to toy with open source at home, try a Linux live CD such as this one. The whole Linux OS boots from CD, installing nothing on your hard drives. It’s a good and safe way to learn. Just don’t do it at work - IST isn’t quite there yet.