align-open-comment-modes

align-open-comment-modes is a variable defined in `align.el'.
Its value is

(vhdl-mode emacs-lisp-mode lisp-interaction-mode lisp-mode scheme-mode c++-mode c-mode java-mode perl-mode cperl-mode python-mode makefile-mode)

Original value was

(emacs-lisp-mode lisp-interaction-mode lisp-mode scheme-mode c++-mode c-mode java-mode perl-mode cperl-mode python-mode makefile-mode)

Documentation:
A list of modes with a single-line comment syntax.
These are comments as in Lisp, which have a beginning, but end with
the line (i.e., `comment-end' is an empty string).

You can customize this variable.