For this list, we looked for quality, open source alternatives to software that has a reputation for being expensive. Whenever possible, we included MSRPs for the expensive software, though in some cases, the pricing scheme is so complicated that it's nearly impossible to pin down.

We published a similar list last year, and we've updated and expanded the list for 2011. If you have suggestions for next year's list, feel free to note them in the comments section below.