I'm way out of the loop, but is the issue that they actively make it difficult to use the rendering engine or is it that the cost to modularize it isn't worth the payoff to Firefox itself? A subtle but important distinction IMO. I always felt it was the second, but maybe I was being dense?
I believe it might be still possible with UXP - a hard fork made for Pale Moon project.
Pale Moon is based on a derivative of the Gecko rendering engine (Goanna) and builds on a hard fork of the Mozilla code (mozilla-central) called UXP, a XUL-focused application platform that provides the underpinnings of several XUL applications including Pale Moon. This means that the core rendering functions for Pale Moon may differ from Firefox (and other browsers) and websites may display slightly different in this browser.
They don't try to make it difficult, but they make code changes that make it clear they have no concern for anyone who might be trying to use the engine anywhere other than in a retail build of Firefox, without providing things like deprecation warnings or upgrade paths.
I'm way out of the loop, but is the issue that they actively make it difficult to use the rendering engine or is it that the cost to modularize it isn't worth the payoff to Firefox itself? A subtle but important distinction IMO. I always felt it was the second, but maybe I was being dense?
I believe it might be still possible with UXP - a hard fork made for Pale Moon project.
They don't try to make it difficult, but they make code changes that make it clear they have no concern for anyone who might be trying to use the engine anywhere other than in a retail build of Firefox, without providing things like deprecation warnings or upgrade paths.