I mean custom as in "I wrote it myself". It's not based on a slow and bloated UI framework. Hopefully it's fairly standard from a Windows point of view though.

If you want to know more, I have lots of dev videos on my youtube channel. https://www.youtube.com/@puredevsoftware

To me that’s a turnoff, you might get an IDE where the speed is faster, but updates and fixes will be slow to come because the team could not get over NIH.

Yeah, whenever I see something like that, my first thought is, “Doesn’t work like other apps on your OS, so will be a pain to get used to, will have weird inconsistencies, and won’t integrate properly with OS features that come standard with all other apps you run.