Non-Linux FOSS: Rearrange Your Furniture, Not Your Spine
My family is in the middle of moving from one house to another. Part of that move involves arranging furniture. I'll be honest, I can move a couch across a room only so many times before I start to think perhaps there's a better way. Thankfully, there is.
Although several 3-D house-modeling packages exist, and a couple are even on-line, nothing seems to work quite as simply as Sweet Home 3D. It's both a 3-D and 2-D layout tool, and it comes with a wide variety of pre-made furniture and window/door graphics to get you started. I was able to design a rudimentary living room in about two minutes (Figure 1), and that included installation time! Sweet Home 3D is an open-source Java application that comes with a nice Windows executable installer.
Figure 1. Living Room Design
You might be thinking, if it's Java, won't it run on other platforms too? Well, yes, of course! It might not be as simple as the Windows executable installer to use it on OS X or Linux, but it's Java, so it's cross-platform-compatible. If you need to design a layout for your house, but don't want to haul furniture around to see what it looks like, I highly recommend Sweet Home 3D (http://www.sweethome3d.com).