Just checking in to learn the current status of FEBE, CLEO, and OPIE wrt Pale Moon v. 27, which has been the current version for a while now. For example, does FEBE 8.3.1 seem to run okay in PM 27? CLEO 6.0.1? OPIE 22.214.171.124-signed? Or have you begun to update these specifically with PM in mind?
To my knowledge, FEBE 8.3.1 and the current versions of CLEO and OPIE all run fine on Pale Moon. When Mozilla finally deprecates XPCOM and XUL (with Fx v57 to be released in November of this year), I plan to re-release the extensions (with version numbers starting with '10') for Fx clones and forks that still support XPCOM and XUL. This, of course, includes Pale Moon.
FEBE v10 will initially be the same as FEBE v8.3.1 and I will make modifications as needed to fully support the XPCOM and XUL compatible versions of the Fx clones and forks (but not Firefox itself. Most of my extensions cannot be written properly with the WebExtensions platform that Fx and Chrome adopted).
I will be retiring from my day job at the end of May this year. At that time I will be able to devote the attention needed to do the modifications.
WebExtensions is far too limiting to write extensions as sophisticated as FEBE. FEBE requires the ability to access a users bookmarks, passwords, cookies, etc., and the ability to write to the user's hard disk. WebExtensions (at least at the current stage) cannot do this.
OPIE for sure and probably OPIE2 should be work with Pale Moon. Offhand, I cannot remember if OPIE2 contains code only applicable to Firefox versions after v27. (Thanks for the kudos! I'm very much looking forward to getting back to extension development on a more permanent basis.)