WriteMonkey, WriteRoom, and alternativeto.net
I like WriteRoom on the Mac, but I’d never found something I liked like that for Windows. Periodically I’d look for such an editor and try a few but none of them really clicked for me. This time I found WriteMonkey. It seems to get the job done but only some time will tell for sure.
Also alternativeto.net has been handy more than once for rooting out a other-or-cross-platform alternative for me. Using a Windows desktop, a Mac laptop and Linux here and there for servers and VMs sort of complicates finding good software for all situations.