Stardock Software (stardock.com)

The fact that this company builds both sucessful professional apps (fences, windows blinds) and great games (sins of a solar empire) makes it something of a singularity

I enjoyed using Object Desktop by them when I was still using OS/2 Warp

I use Start11 on my work computer. It allows me to resurrect a lot of the features that I liked on earlier versions of Windows. Their software is also extremely stable.