In Windows, I've had great luck with Notepad++ at
http://notepad-plus-plus.org.
It allows you to replace text or regular expressions. So, for instance, if you need to change a room name, you can do so. Or if you want to see combinations of text (e.g. say.*male to look for gender-specific text) then Notepad++ allows this.
I've also found Notepad++ wonderful when making changes I don't want or need to compile. For instance, a random text table, or general narrative stuff. If I'm writing in Notepad++, it feels like I'm working on pure writerly bits. I don't need to worry about the technical side.
A big risk is that, if you save something in Notepad++ and changed something in Inform without saving, you lose the IDE's changes. However, if nothing was edited in Inform, then you get the Notepad++ changes saved over.
Notepad++ will also pick up on any changes made in Inform before reloading. So you have a buffer there if you mistakenly open two files at once.
When doing this sort of major thing, you should ALWAYS back up the source code first in case anything bad happens. Often you can compare the source before and after to see what went wrong.