I'm using Lazarus without LCL stuff on Windows, Linux and Mac OS X. Especially tools like code refractoring and jumping to the definition of a procedure/function are things I don't want to miss anymore. In case I don't have Lazarus available or I just want to open a file for quick editing, I use Geany on Linux and Notepad++ on Windows. (Geany can be considered an IDE, while Notepad++ is not.)