QEdit on DOS... now that brings back some memories! I went in for their flagship TSE (The Semware Editor) when it came out and was duly impressed.
I have used Notepad++ as my regular non-IDE editor for probably 15 years; there are a handful of (semi-)unique features that I really appreciate. I'm guessing UltraEdit keeps its user base for similar reasons.
A long time ago... used it a lot in 80x50 line text mode, lightening fast, good macro and configuration options (ISTR a separate tool to "reconfigure" the main binary). Had many of the same default bindings as the Borland IDEs, handy since the TurboC IDE used to run out of steam around 1000 loc or so, that's when I learned Makefiles.
Never took to TSE, sequence of bad experiences with stability.