Something I run into all the time is a customer trying to use a font with OpenType features in an application that doesn't support it. I usually search font "(application name) OpenType support" and sift through forum posts but it's hard to know for sure without installing the app and testing it. I'm starting this thread to list the applications I know of that don't have basic OpenType feature support. If you know of any application with no OpenType support, please add them to this thread.
By basic OpenType support, I mean contextual alternates (calt) and kerning (kern). This should be based on the current version of the app.
Here's what I've got so far: