Emacs support for ACL2
Many successful users of ACL2 run it in a shell under the Emacs
editor. If you do so, then you may wish to load the distributed file
In particular, the above file provides the ACL2-Doc browser, a convenient tool for viewing, in Emacs, documentation for both the ACL2 system and the documented community books, as well as custom manuals. See ACL2-Doc.
If you are not comfortable with Emacs, you may prefer to use an Eclipse-based interface; see ACL2-sedan.