The only programs I currently run are the main editor (SCXE, StarForge, or SCMDraft, depending on my need) and possibly Windows Media Player (sorry, but that's the only music player I've got installed in this lousy computer). There are the occasional times where I need other editing utilities, like GUEdit, that I use. But when I do run them, I close the main editor. Sometimes, I open a browser (when connected to the internet) so I can browse forums like this, possibly to ask questions or find new ideas and concepts. Or find something to motivate me to continue mapping.
Sometimes I run some online games in the background, with me being afk (or vending, in the case of Ragnarok Online).