Proof General is a generic interface for proof assistants based on the Emacs editor. It supports files for several proof assistants including Coq file (.v), an EasyCrypt file (.ec), or a PhoX file (.phx). Historically, other proof assistants such as Isabelle.
References:
Proof general Documentation
Isabelle Proof General Documentation
Cheat Sheet
DISCONTINUATION OF ISABELLE PROOF GENERAL